Russia launched a fresh wave of pre-dawn missile and drone attacks on Kyiv and several other large Ukrainian cities on Tuesday, the second day of a deadly, far-reaching bombing campaign that comes as Moscow fights to fend off a Ukrainian offensive on Russian soil.

The early-morning barrage hit a hotel in the central Ukrainian city of Kryvyi Rih, killing four people and wounding several others, according to the governor of the Dnipropetrovsk region, Serhiy Lysak, who posted photographs showing the ruins of the hotel. The local authorities said two people also were killed in the city of Zaporizhzhia and that debris from downed missiles or drones sparked small fires in the capital, Kyiv.

Russia has over the past year fired large volleys roughly once a month in attempts to overwhelm Ukraine’s air defense systems with drones and missiles launched from multiple directions.

Many areas close to the front lines in Ukraine come under daily assault from Russian forces, but this week’s strikes have revived a broader sense of fear among civilians in bigger cities as air raid sirens blare, and drones and missiles tear into hotels and residential buildings. Attacks on energy infrastructure have disrupted water and power supplies, deepening the hardships of war.

“It was hard yesterday,” said Samir Mamedov, 33, a Kyiv resident who works in business development. “We were running to the shelter because it was a big bombing.”

But he added that people in his circle were now accustomed to the conflict. “Last year we thought that the war would be finished soon, but everyone is getting used to the idea that this war is not going to end,” he said.

The barrage that began on Monday comes at a tumultuous moment, just three weeks after Ukraine launched an incursion into the Kursk region of southern Russia.

The commander of Ukraine’s armed forces, Oleksandr Syrsky, said on Tuesday that Ukraine has taken control of 100 settlements in Kursk. The Russian authorities have repeatedly insisted the situation was under control and that its forces were repulsing the attack. The claims could not be confirmed independently.

President Vladimir V. Putin of Russia had promised a decisive response, and his spokesman, Dmitri S. Peskov, reiterated that message on Monday, saying that Russia would inflict “an appropriate response.”

It was unclear whether the attacks this week constituted that retaliation. President Volodymyr Zelensky of Ukraine vowed on Tuesday to “pay Russia back” for the strikes.

“Crimes against humanity cannot be committed with impunity,” Mr. Zelensky said in a post on Telegram.

Since the incursion into Russia began, Ukrainian troops have gone beyond Kursk to the neighboring region of Belgorod. On Tuesday, the regional governor of Belgorod, Vyacheslav Gladkov, said Ukrainian forces had launched 23 drones and dozens of munitions at towns and villages in the area over the past 24 hours.

He also claimed there were reports of Ukrainian troops were trying to break through the border in the region, the Russian state news agency Tass reported, saying that the situation remained “difficult but under control,” without elaborating. That claim could not be independently verified and there was no immediate comment from Russia’s Ministry of Defense or from Ukrainian officials.

On Tuesday, Ukraine’s air force said it had shot down five cruise missiles and 60 exploding drones, suggesting that the assault may have been smaller than the one the previous day, when Russia launched more than 200 drones and missiles. Mr. Zelensky called Monday’s attack “one of the largest” his country has faced since Russia’s invasion began 30 months ago.

At least four people were killed in Monday’s barrage, according to the Ukrainian authorities.

On Tuesday, air alarms went off throughout most of the country. In Kyiv, a loud explosion echoed in the downtown area around dawn. The city’s military administration said that the capital was under a “combined rocket and drone attack of the enemy,” and the authorities later said that falling debris from intercepted missiles or drones had set grass on fire in two city parks.

Ukraine relies on Soviet-legacy interceptors, which it had in great numbers before the invasion in 2022, and an array of Western-provided air defenses to shoot down incoming missiles and drones. They include long-range Patriots; the midrange NASAMS; and short-range, shoulder-fired Stingers, intended to prevent missiles from slipping through to hit targets.

Kyiv, though, has been attempting to ramp up its domestic military production to make itself less reliant on supplies from NATO allies.

Mr. Zelensky told journalists on Tuesday that the country’s defense industry had created and tested Ukraine’s first domestically produced ballistic missile. He gave no further details, and the claim could not be independently verified.

Still, Ukraine’s relative success in shooting down the incoming fire is in large part a testament to the tens of billions of dollars in military aid the country has received since February 2024.

President Biden on Monday reiterated his “unshakable” support for Ukraine and said that his government would continue to lead a coalition of more than 50 nations that has rallied help for the country.

“I condemn, in the strongest possible terms, Russia’s continued war against Ukraine and its efforts to plunge the Ukrainian people into darkness,” he said, a reference to one of the main targets of Monday’s strikes: energy infrastructure.

The attacks this week came against the backdrop of grinding battles in eastern Ukraine.

One of Ukraine’s aims with the incursion into the Kursk region was to force the Kremlin to divert troops from the front lines in the Donetsk region of Ukraine, where they have been advancing on the city of Pokrovsk, an important transport hub for Ukrainian forces.

But Russia has been pressing on with its offensive in the Donetsk region. General Syrsky said that Russian forces were attempting to cut off a road that runs northeast from the city and is used as a resupply route, adding that Moscow is “increasing its presence on the Pokrovsk front.”

Military analysts have for months argued that Ukrainian military resources are already stretched thin, raising questions about whether it can continue attacking inside Russia while maintaining its defenses in the east.

In the darkness of the cellar in the eastern Ukrainian town of Toretsk, the soldiers did not know how close the Russian glide bombs were landing. But the sudden change in air pressure that accompanied bone-rattling booms testified to the bombs’ destructive force as they tore into nearby buildings.

At dawn, during a lull in the attacks, several Ukrainian soldiers dashed out and saw a fire triggered by one of the bombs still raging through the ruins of a building about 150 yards away — the narrow margin between life and death.

There are many ways to kill and be killed in Russia’s war with Ukraine, but Ukrainian soldiers say that glide bombs are perhaps the most terrifying. They are free-fall bombs, many left over from the Soviet era, but now outfitted with pop-out wings that feature satellite navigation, turning them into guided munitions.

Referred to alternatively as “KABs” or “FABs,” they weigh between 500 and 6,000 pounds and are packed with hundreds of pounds explosives. A single blast can reduce a high-rise apartment building to rubble and obliterate even concrete fortifications.

“It is scary and very fast,” said Stanislav, a 28 year-old Junior Sergeant with Ukraine’s 32nd Mechanized Brigade, as Russian fighter jets unleashed the powerful guided bombs in the direction of his unit. “I just pray every time.”

In recent months, Russia has used the bombs to devastating effect, tilting the balance of fighting in eastern Ukraine in Moscow’s favor and allowing Russia to continue to make steady gains in Donetsk region. The bombs have also allowed Russian forces to raze whole towns and villages with ever greater speed.

In the midst of the midsummer fighting around Toretsk, journalists from The New York Times were allowed to visit the town one night to witness the challenges facing Ukrainian forces as they try and hold positions under withering bombardments.

“The same thing every day,” said Jackson, a 29 year-old Junior Sergeant who commands a drone platoon for the 32nd. “We arrive at a position, they launch KABs, we hide, block our ears and open our mouths so as not to get a concussion,” he said.

Like Stanislav and others interviewed, he provided only his first name according to military protocol.

With Ukrainian forces almost completely pushed out of the small town of Niu-York a few miles to the south, the battle for Toretsk, a former mining town, is now underway.

Along with the Russian advance in the direction of Pokrovsk, a critical Ukrainian logistics center about 40 miles to the southeast, the enemy’s push into Toretsk is threatening to undermine the defense of the Donetsk region.

Ukrainian soldiers fighting in the hottest areas of the front say they are largely outgunned and outmanned. And Russia’s continuing ability to unleash unrelenting aerial bombardments, they said, continues to play a critical role in forcing them from even some of their most heavily fortified positions.

Finding a way to counter the threat remains a top military and diplomatic priority even as Kyiv engages in a bold gambit to flip the momentum of the war by mounting a cross-border incursion into the Kursk region of Russia.

Kyiv is hoping that the offensive will force Moscow to deploy more forces to defend that region, and thus ease the pressure along the eastern front by drawing in some of Russia’s better fighting forces.

So far, however, the Kremlin appears to be intent on maintaining its own offensive operations in eastern Ukraine and is pounding away at towns like Toretsk as relentlessly as ever.

It is a punch and counterpunch strategy for both armies — battered by years of brutal fighting, with each side wagering that their opponent will find themselves overstretched and newly vulnerable.

Ukraine has been developing its own long-range strike capabilities and is increasingly using domestically produced missiles and drones to target the airfields in Russia where the warplanes begin their bombing runs.

But Russian warplanes still managed to launch some 750 glide bombs in a single week in August, Mr. Zelensky said.

Even Ukrainian soldiers accustomed to years of artillery bombardments shudder at the destructive power of the weapons.

A 152-millimeter artillery shell — which Russia fires by the thousands every day — contains a bit more than 13 pounds of explosive material. A commonly deployed glide bomb, the FAB-1500, is packed with more than 1,300 pounds of explosives.

Since the bombs do not use propulsion or give off a detectable heat signature, they are hard to spot. They can be launched from Russian warplanes dozens of miles behind the front lines, relatively safe from Ukrainian air defenses.

When Russian planes fly closer the front, soldiers said, they are protected by Russian surveillance and attack drones that saturate the skies, searching for Ukrainian soldiers armed with portable antiaircraft missile systems.

“To shoot down a plane, you need to keep it in the sights for eight seconds and only then release the missile,” said Petro, 38, a Senior Sergeant of the 2nd Battalion of the 24th Mechanized Brigade. He previously fought around Toretsk and is now defending the nearby stronghold of Chasiv Yar.

Eight seconds in the open, he said, is an eternity. A Ukrainian defender can see the Russian jet streaking through the sky, he said, without being able to do anything to stop it because of the threat posed by the drones.

The best way to slow the pace of the attacks, Ukrainian officials have argued, is to hit the aircraft used to deliver the weapons, either on the ground or in the air.

Sgt. Jackson recalled the first time a glide bomb exploded near his position.

“I had such a feeling in my body that it was as if the wind swept through me at a very high speed, through each of my organs,” he said. “The feeling is very frightening.”

He sat on a battered cot in a basement bunker in the faint glow of video monitors, less than a mile from the Russians.

Outside, the charred and twisted metal skeletons of at least four vehicles littered the roadside out of the city, reminders that any movement can be deadly. Before they were destroyed, they had been used by volunteers to help civilians flee; now it is too dangerous for organized evacuations, city officials said.

It is not clear how many civilians remain in Toretsk, but by the end of July there were believed to be fewer than 3,500, Vasyl Chunchyk, the head of Toretsk military administration, said in an interview. More than 60,000 have been forced to flee the area and those who remain live mostly subterranean lives.

“There is not one building which has not been damaged or destroyed,” Mr. Chynchyk said.

The police department, the local administration building and the fire station have all been destroyed and the Ukrainian military works in the ruins.

While the list of places obliterated by Russian forces continues to grow, experiencing the annihilation of a city in real time remains deeply shocking even for the soldiers who have witnessed countless scenes of desolation and destruction.

“When you drive into a ruined town, it’s like hopelessness,” Stanislav said. “This town is crying.”

A few hours after he spoke, his unit’s basement bunker was destroyed by Russian artillery. Fortunately, the soldiers said, they all escaped with only minor injuries and were setting up elsewhere to continue the fight.

Evelina Riabenko contributed reporting from eastern Ukraine.

Two jaguar cubs burned to death, their small bodies carbonized. Tapirs with raw, bloodied paws had been scalded by smoldering cinders. Nests of unhatched eggs from rare parrots were consumed by flames as tall as trees.

Wildfires are laying waste to Brazil’s Pantanal, the world’s largest tropical wetland and one of the most important biodiversity sanctuaries on the planet.

And the blazes, the worst on record since Brazil started tracking fires in 1998, are taking a deadly toll on wild animals, including at-risk species that scientists have been working for decades to protect.

“We’re watching the biodiversity of the Pantanal disappear into ash,” said Gustavo Figueirôa, a biologist working for SOS Pantanal, a conservation nonprofit. “It’s being burned to a crisp.”

The Pantanal is a maze of rivers, forests and marshlands that sprawl over 68,000 square miles, an area 20 times the size of the Everglades. About 80 percent lies within Brazil, with the rest in Bolivia and Paraguay.

Usually flooded for much of the year, the Pantanal in recent years has been parched by a string of severe droughts that scientists have linked to deforestation and climate change.

Since the start of the year, wildfires have burned over 7,000 square miles, an area the size of New Jersey, in Brazil’s share of the Pantanal.

The wetlands, parts of which are on UNESCO’s list of heritage sites because of their rich biodiversity, are home to the world’s biggest parrot, the highest concentration of caimans and threatened wildlife like the giant otter.

They also harbor animals that have evolved in ways distinctive from others in their species, like larger jaguars that dive into flooded plains to fish for food.

Researchers have counted at least 4,700 plant and animal species in the Pantanal, though they say many more have yet to be discovered by scientists.

“There’s so much we still don’t know,” said Luciana Leite, a biologist and a climate campaigner for the Environmental Justice Foundation. “It’s such a special region.”

But the wildfires, fanned by strong winds and searing temperatures, are threatening this natural laboratory, killing or injuring giant anteaters, lowland tapirs, marsh deer, hyacinth macaws and caimans.

The flames have caught even jaguars, normally agile enough to escape most dangers. Three have been found dead since the fires erupted, while four others were rescued and treated for burns, according to conservationists in the region.

“If the jaguar — an animal that runs, climbs, swims — is being affected on this scale, what chance do slower animals have?” said Enderson Barreto, a veterinarian and a director of the Response Group for Animals in Disasters, a volunteer organization working in the Pantanal.

Jaguars are listed as vulnerable in Brazil, which is home to about half of the world’s population of the animal. Now, the fires are approaching a reserve that is home to the world’s highest density of jaguars (four to eight animals for each 40 square miles), and experts fear that the death toll of jaguars, and many other animals, may climb.

“We’re really nervous watching this unfold,” said Mr. Barreto, who is working on the front lines of the rescue efforts inside the Pantanal. “The outlook is not good.”

Scientists say it is too early to say precisely how many animals are dying in the blazes, since many are perishing in remote regions that rescue workers cannot reach. But they fear the toll could exceed that of fires that ravaged the region in 2020, killing some 17 million animals and burning nearly one-third of the Pantanal in Brazil.

“We’re not only witnessing a repeat of a tragedy,” Dr. Leite said. “It’s actually a situation that’s much worse.”

One animal that became a victim was named Gaia and had played a key role in the Pantanal’s fledgling ecotourism industry for a decade. Spunky and social, Gaia, a 130-pound spotted jaguar, did not shy away from the pickup trucks carrying tourists from a nearby ecolodge. She became a local celebrity among wildlife enthusiasts.

Then, this month, the flames arrived at breakneck speed. Gaia didn’t have time to flee.

The news jolted Mr. Figueiroa, who had monitored the jaguar and her siblings when they were still cubs. “That was one of the best sightings of my life,” he said, lifting a pant leg to reveal a tattoo of Gaia’s sister on his calf.

“When I saw Gaia burned, turned into coal, I could just imagine the pain she must have felt,” Mr. Figueiroa added. “It was a feeling of frustration and despair and helplessness.”

The fires have also killed at least three giant anteaters, mammals known for their distinctive long snout and two-foot-long tongue, which they use to scoop up insects.

Believed to have evolved over millions of years, the species is threatened with extinction in Brazil, and its population there has shrunk by 40 percent over the last two decades, said Flávia Miranda, president of the Tamanduá Institute, a nonprofit working to protect anteaters.

“With the loss of these animals,” Dr. Miranda said, “we lose an evolutionary story that has not yet been fully told.”

The flames from the fires have reached tree crowns and scorched 80 percent of a crucial nesting area for hyacinth macaws, large, bright blue parrots that conservationists consider vulnerable and whose population is declining.

The blazes have also disrupted food chains, leaving behind a barren landscape devoid of water and essential food sources, like plants, insects and smaller animals.

Experts think the wildfires will continue at least until October, when the expected rainy season may bring some relief. The flames are intensifying pressure on an ecosystem already stressed by unusually frequent fires in recent years, casting doubt on whether it can fully recover.

If it doesn’t, countless species may lose their last sanctuaries in South America, including the lowland tapir, according to Patricia Medici, a biologist and conservationist who studies the species. “In the Pantanal,” she explained, “the tapir is in paradise.”

For scientists like Dr. Leite, who have devoted much of their lives to safeguarding vulnerable wildlife in this region, the future looks bleak. She wonders, she said, whether the Pantanal, a rare bastion of nature where humans can still witness wildlife in abundance, will remain intact for the next generation.

“I don’t know whether my son will have the privilege to look a jaguar in the eye, like I have so many times,” Dr. Leite said, wiping away tears. “We’re losing this really magical place.”

Lis Moriconi contributed reporting.

Making another heavy push to work with China in the waning months of the Biden administration, Jake Sullivan arrived in Beijing on Tuesday for talks aimed at showing that the United States and China can manage their differences.

The U.S. national security adviser began his fifth meeting in less than 18 months with China’s top foreign policy official, Wang Yi, as the Biden administration seeks to reinforce its strategy on China despite uncertainty over the future of American foreign policy.

There is much to talk about — but probably little on which they will agree.

Mr. Sullivan plans to discuss working with China on limiting the spread of fentanyl and expanding high-level military contacts. He will also stress the United States’ position on Taiwan and its concerns about China’s support of Russia.

China indicated it would raise its own objections during the talks — including over America’s support for Taiwan, the island democracy Beijing claims, and U.S. controls on exports of technology to China.

Beijing wants the United States to ease its pressure on China, in the hope that it would set the tone for smoother relations with the next U.S. administration, analysts said.

“China’s priority is to maintain the stability of China-U.S. relations in the last several months of Biden’s presidency,” said Zhao Minghao, an expert on U.S.-China relations at Fudan University in Shanghai.

The prospect of a potential meeting between President Biden and China’s leader, Xi Jinping, before Mr. Biden’s term ends, is likely to come up. (It was unclear if Mr. Sullivan would meet with Mr. Xi during his three-day visit.)

Here are some of the issues Mr. Sullivan and Mr. Wang are expected to broach:

Taiwan and Ukraine

Perhaps the biggest flash points in relations between China and the United States are Russia’s war in Ukraine and China’s increasing aggression toward Taiwan.

Mr. Sullivan is likely to urge China to reduce its support to Russia, which the United States and NATO say has helped sustain Russia’s war effort, now in its third year. China buys huge quantities of Russian oil and supplies Russia with dual-use technology that can be applied to the battlefield, U.S. officials say.

Beijing is unlikely to turn its back on Moscow, its only major-power partner in counterbalancing the United States.

Chinese officials will seek to criticize U.S. support for Taiwan, which Mr. Xi has threatened to take by force, if necessary. Beijing accuses Washington of promoting “Taiwan independence” by supplying the island with arms and allowing for exchanges between American and Taiwanese officials.

China said in a statement on Sunday that the United States needed to do more to repair relations. “The United States has kept containing and suppressing China,” a foreign ministry statement said. The relationship, it said, is “still at a critical juncture of being stabilized.”

Taiwan was “the first and foremost red line that must not be crossed,” the statement read.

Technology Controls

Mr. Sullivan has championed the Biden administration’s export controls designed to prevent China from getting its hands on advanced American semiconductors, or microchips, that can be used to develop weapons or computing power that could threaten U.S. national security.

That has frustrated China, which has struggled to catch up with the United States in designing advanced chips despite investing billions of dollars in research. Beijing says the export controls are aimed at stunting China’s rightful development.

The restrictions, which were first introduced in October 2022, have had far-reaching consequences by forcing countries to shift, or consider shifting, some production of semiconductors out of Asia back to North America and Europe.

It is unclear what the long-term implications of U.S. export controls will be. China has seized on the restrictions to redouble efforts to become more technologically self-sufficient. Brokers have also used proxies to smuggle banned chips into China.

Will Xi and Biden Meet Again?

Mr. Sullivan’s visit could lay the groundwork for one last summit between Mr. Xi and Mr. Biden. Discussions between Mr. Sullivan and Mr. Wang were key to organizing last November’s meeting.

Though he will only serve one term, and one that was disrupted by the Covid pandemic, Mr. Biden could be the first president not to travel to China since President Carter.

Mr. Biden has visited China before, when he was vice president in 2011, a trip remembered for his stop at a local Beijing restaurant for noodles and dumplings. If a state visit is not possible, Mr. Xi and Mr. Biden could potentially meet at the APEC summit in Peru in November.

Of course, China may not be interested in Mr. Biden’s lame duck presidency and could be focused on how best to approach the next administration. Writing in Foreign Affairs magazine this month, the Chinese international relations scholars Wang Jisi, Hu Ran and Zhao Jianwei said Beijing sees little difference between a Trump or Harris administration; they will both be driven by domestic pressure to be tough on China.

“Beijing is preparing itself for the outcome of the U.S. elections with great caution and limited hope,” they wrote.

Olivia Wang contributed reporting.

The flames and smoke from a burning Mercedes-Benz electric sedan spread rapidly through the underground parking lot of an apartment complex in South Korea this month. The fire damaged almost 900 cars, and 23 people suffered smoke inhalation.

It took firefighters more than eight hours to put out the blaze, which reached temperatures above 1,500 degrees Celsius, according to officials in Incheon, the city near Seoul where the fire broke out around dawn on Aug. 1.

Fires are much less common in electric vehicles than in gasoline-powered ones, and the cause of the Incheon blaze has not been disclosed. But across South Korea, one of the world’s biggest car producers, it caught the public’s attention because of its scale and intensity, and it raised safety fears that some say could impede the government’s aggressive push toward electric vehicles.

One popular secondhand car sales platform, K Car, said that listings by E.V. owners hoping to sell their vehicles had nearly tripled since the fire.

“I know that E.V.s might be the more environmentally friendly choice, but I’m still afraid of it catching fire,” said Lee Min, an office worker in Seoul who is hoping to buy her first car. “I got even more scared after seeing the Incheon incident.”

News coverage of the fire, and social media’s reaction to it, have focused on perceived risks from battery charging, and car makers and government officials have tried to assuage those fears. The municipal government in Seoul said that by the end of next month, it would prevent E.V.s from being fully charged in parking lots beneath residential buildings, limiting them to 90-percent capacity to prevent the risk of overcharging, though some experts have questioned whether that would do much to improve safety.

Some automakers, including Mercedes-Benz Korea, have offered owners free safety checks on their E.V.s and identified their battery suppliers. The German automaker said a Chinese company, Farasis Energy, had supplied the battery in the sedan that caught fire. Farasis did not respond to a request for comment.

“The popularity of E.V.s is going to decrease for the next while,” said Lee Ho-Geun, a professor of automotive engineering at Daeduk University in the city of Daejeon. “People are scared.”

Before the fire, South Korea’s E.V. market had been growing at a clip, accounting for 9.3 percent of new cars in the country last year, according to official data.

The national government has rolled out subsidies for buyers as well as tax breaks for E.V. makers, part of an effort to reduce greenhouse gas emissions by around 40 percent by 2030, compared to 2018 levels. It hopes to end sales of gasoline-powered cars by 2035. The government has spent 371.5 billion Korean won, or about $280 million, to install charging facilities.

There have been almost 200 electric vehicle fires across the nation over the past six and a half years, according to government figures. That does not include a fire at a lithium battery factory near the capital that killed 23 workers in June, one of the country’s worst industrial disasters in recent years.

Lithium, which is used in most E.V. batteries, can store large amounts of energy in a small space, but it burns intensely when on fire. There are no government-approved extinguishers designed for lithium battery fires, according to South Korea’s national fire department.

Electric vehicles catch fire less frequently than other types of vehicles. For every 100,000 E.V.s, there are just 25 fires, compared to 1,530 for gasoline-powered vehicles, according to the United States’ National Transportation and Safety Board. Battery fires, however, can be much larger and more damaging, Mr. Lee, the engineering professor, said.

Despite the statistics, fires have raised concern about E.V.s’ safety in many countries, including the United States. The Incheon blaze resonated in South Korea because many people live in apartment blocks and share underground parking lots.

Security video footage released by news outlets shows smoke coming out of the Mercedes EQE 350 before it burst into flames. The vehicle, which was on a floor with a capacity for about 2,000 cars, was not plugged in at the time, according to the local fire department.

Hundreds of residents have been temporarily moved out of the building while repair work takes place.

Days after the fire, Mathias Vaitl, the president of Mercedes-Benz Korea, said the company would pay 4.5 billion won, or around $3.4 million, to affected residents. Mercedes-Benz said in a statement it was deeply sorry to all impacted by the fire, but did not comment on the cause.

The German automaker released a list of its battery suppliers in the wake of the fire, and other companies followed suit, including Hyundai and Kia. Over the weekend, the government said it would require all automakers to disclose their battery suppliers by early next year.

The government discussed comprehensive measures to alleviate public concern and ensure that such a mass fire doesn’t happen again, a spokeswoman said at a televised briefing on Sunday.

Mr. Lee, the engineering professor, said the government needed to upgrade charging infrastructure and fire-response systems. He said that a 90-percent cap on battery charges, on its own, was unlikely to prevent all fires.

“It’s like asking a smoker to smoke two cigarettes instead of three,” he said.