Mark Carney, who has never held elected office but has a long résumé in economic policymaking and investing, was sworn in Friday morning as Canada’s 24th prime minister. He will have no time to ease into his role.

Canada is experiencing a period of severe instability as its relationship with its closest ally, the United States, has been plunged into an extraordinary crisis since President Trump was elected and began unleashing attacks on its economy and sovereignty.

Mr. Carney will attempt to negotiate with Mr. Trump, who has unfurled a slew of tariffs and threats on Canada including a desire to take over the country entirely, while simultaneously heading straight into a campaign for a federal election.

He does not hold a seat in Parliament, and his party controls only a minority of the seats in the House of Commons, which means he has little choice but to immediately call for a federal election, likely to take place by May.

Mr. Carney, who turns 60 on Sunday, replaces Justin Trudeau who led Canada for nearly a decade. He was elected as Liberal Party leader on Sunday by some 152,000 members of the party, securing 86 percent of the vote.

He had served as governor of the Bank of Canada during the global financial crisis of 2008 and later as governor of the Bank of England — the first and, so far, only foreigner to be hired to the job — from 2013 and through the Brexit transition.

Before becoming a central banker, he worked at Goldman Sachs for more than 10 years. Since leaving the Bank of England he has served in top positions on corporate boards and has emerged as a key global advocate for green investment.

Mr. Carney has made it clear that he plans to continue taking a hard line against Mr. Trump, while also trying to reach a trade deal with the president. Canada has applied two rounds of retaliatory tariffs against U.S. exports and said it was prepared to do more.

“My government will keep our tariffs on until the Americans show us respect — and make credible, reliable commitments to free and fair trade,” he told the party faithful in Ottawa on Sunday as he accepted the role of party leadership.

And in a sign that he is looking for new best friends for Canada now that its relationship with the United States is badly frayed, his first overseas visits will be to London and Paris.

Dealing with the complex problems that Mr. Trump’s statehood threats and tariffs create for Canada will leave little time for anything else, but Mr. Carney has made policy promises that suggest he is a centrist.

He has vowed to introduce an era of fiscal prudence and to cut taxes, while leveraging his business experience to help Canada attract investments that can help boost the country’s economy.

Mr. Carney will also need to turn his attention to pressing domestic issues, like a persistent high cost of living and the effects of record immigration that spurred Mr. Trudeau’s resignation.

But the economic fallout from the suite of tariff measures imposed by Mr. Trump, will dominate Mr. Carney’s first days in office.

He will need to try to stop Mr. Trump from bringing in fresh surcharges on more Canadian goods as he has threatened. Economists say they expect that the current measures taken against Canada by the U.S. administration, as well as the slowdown in investment that comes from the uncertainty around what will happen next, will hurt the Canadian economy and could push it into a recession.

Then there is the looming election. Mr. Carney will need to prove that despite never having run for political office, he is still the best person for the job, not just to a group of party members who broadly agree with him but to the entire electorate.

In the federal election he will face off against Pierre Poilievre, the Conservative leader who has helped his party gain a robust lead in public opinion polls and collect almost double the amount of fund-raising dollars as the Liberals in 2024.

Mr. Trump’s arrival in the White House, however, has upended the political landscape.

A lifelong politician who knows how to deliver a punchy slogan, Mr. Poilievre, 45, is trying to pivot his messaging, political analysts say, to position himself as the strongest candidate to take on Washington, while not alienating pro-Trump conservatives in Canada.

Mr. Poilievre’s main angle of attack had long been to present Canadians with all the ways that the Liberal Party had “broken” Canada, with a focus on crime, housing prices, an unpopular consumer carbon tax and a surge in immigration.

But Mr. Trump’s ascent and his attitude toward Canada, coupled with the resignation of Mr. Trudeau, who had become deeply unpopular, have nearly evaporated the Conservatives’ lead in a remarkable reversal.

Several recent opinion polls have shown that, under Mr. Carney’s leadership, the Liberals would have a chance of eking out a victory.

From his expansive qualifications in the finance world, there’s little doubt of Mr. Carney’s ability to get his message across in a boardroom or a monetary policy meeting. In his central banking roles he was often seen as being sermonic, and at times dismissive of the news media.

But he’ll need to find a common touch and a different level of engagement to be able to campaign effectively.

Mr. Carney’s challenge will be to quickly master “retail politics” — the art of energizing a room with a speech, making individual supporters feel important and heard and finding a way to engage with the news media that gets his point across clearly, said Fen Hampson, a professor of international affairs at Carleton University in Ottawa.

“Those glad-handing skills do not come automatically to someone who’s spent his life being a banker,” Mr. Hampson said. “His Achilles’ heel is that his communication skills and his retail politics skills are not finely honed yet.”

Top U.S. representatives told a Canadian delegation on Thursday that there was no way Canada, or any other country in President Trump’s cross hairs, could avoid a new round of sweeping tariffs on April 2, according to two people with direct knowledge of their conversation.

Any negotiations to remove some tariffs or even strike a more comprehensive trade deal would come after that date, American officials told their Canadian counterparts at a meeting in Washington, D.C. Mr. Trump, through an executive order, has ordered an in-depth examination of trade between the United States and several partners, including Canada, and the imposition of “reciprocal” tariffs beginning on April 2, to match surcharges other countries impose on U.S. goods.

The United States was represented in the meeting by Commerce Secretary Howard Lutnick and U.S. Trade Representative Jamieson Greer. Canada was represented by Finance Minister Dominic LeBlanc, Industry Minister François-Philippe Champagne, Ontario Premier Doug Ford and Canada’s ambassador to the United States, Kirsten Hillman.

The Canadian officials left the meeting, which lasted more than an hour, with a clearer — but not necessarily more optimistic — sense of what lies ahead, according to two of them with direct knowledge of what transpired, who requested anonymity because they were not authorized to brief the press about it.

While the Trump officials made clear their pledge on reciprocal tariffs, Mr. Trump has shown a repeated penchant for vowing to press ahead with tariffs only to decide at the last minute to back down or grant a reprieve.

The meeting was an effort to inject a calmer approach to the relationship between the two countries, even as Mr. Trump on Thursday continued to level threats against Canada’s sovereignty.

The Canadian officials said that Mr. Lutnick and Mr. Greer conveyed to them that the Trump administration is very committed to tariffs as a trade policy, and to using tariffs to redefine the United States’ relationship to the world. April 2, they were told, will be a major step in establishing this new doctrine.

Mr. Trump last month directed his advisers to come up with new tariff levels that take into account a range of trade barriers and other economic approaches adopted by America’s trading partners. That includes not only the tariffs that other countries charge on U.S. products, but also the subsidies they give their industries, their exchange rates, and other measures that the president deems unfair.

Mr. Trump has said he needed to take action to even out America’s “unfair” relationships and stop other countries from taking advantage of the United States on trade. But he has made clear that his ultimate goal was to force companies to bring their manufacturing back to the United States.

The Canadian officials were left with the impression that there was a willingness by the United States to brush off the negative reaction that financial markets have already had to the president’s tariffs on Canada, Mexico and China.

The U.S. side explained that there was little Canada or any other nation could do to avert the coming tariffs on April 2. Instead, the administration was planning to go full steam ahead, and then, afterward, consider individual exemptions, changes or broader renegotiations on tariffs with specific countries, depending on market reactions.

After on-again-off-again threats of expansive tariffs, the United States now applies 25 percent surcharges on Canadian steel and aluminum as well as 25 percent on goods that do not comply with the existing trade agreement between the two nations. .

Economists believe the tariffs imposed so far, Canada’s retaliation against U.S. imports, and the overall atmosphere of volatility and uncertainty, could tip Canada into a recession this year.

A Trump administration official said that in the meeting on Thursday, Mr. Lutnick and Mr. Greer had highlighted the Trump Administration’s commitment to pursuing fair trade, and that both countries had recognized the strength and history of their relationship.

Mr. Lutnick has been meeting with numerous foreign officials to ensure that Mr. Trump’s message was heard and acted on accordingly, the U.S. official said. The Trump administration aimed to help U.S. companies prosper in the global marketplace by building balanced relationships, and eliminating trade deficits and foreign restrictions to trade, the official added.

Canadian officials are expected to return to Washington next week to talk with Mr. Greer, they said, and start focusing on more granular detail about addressing two key U.S. concerns raised in the Thursday meting: the digital services tax applied by Canada, and the question of quotas and surcharges on dairy products.

Canada imposes a 3 percent tax on revenues of online businesses, including social-media companies, online marketplaces and online advertising — industries that U.S. firms dominate. The tax has been a key complaint in the U.S.-Canada trade relationship since the Biden administration.

On dairy, Canada and the United States apply quotas and other measures limiting each other’s imports after a certain threshold of imports is reached. Mr. Trump has taken aim at this system, which he agreed to in 2018 as part of the renegotiation of the North American Free Trade Agreement into its successor trade deal, the U.S.-Mexico-Canada agreement.

The officials in the Thursday meeting also said that there was a broader feeling that the tone of the talks could improve with the departure of Canada’s prime minister, Justin Trudeau, who is being replaced on Friday by Mark Carney. Mr. Trump and Mr. Trudeau had fraught personal chemistry dating back to Mr. Trump’s first term.

“The temperature has come down,” Mr. Ford told the news media as he left the meeting on Thursday.

“We leave Washington I think better equipped in making sure we can defend Canadian interests,” Mr. Champagne, the industry minister, added.

Ana Swanson contributed reporting from Washington.

With a trade war brewing, President Trump gave the Mexican president a sign of grudging respect: “You’re tough,” he told her in a phone call last month, according to four people with knowledge of the exchange.

By their most recent conversation, the two leaders were trading compliments and carving out a reprieve from some tariffs in real time, the people familiar with the call said.

When Claudia Sheinbaum became president on Oct. 1, the first woman to ever govern Mexico, there were doubts about how she would handle the relationship with the United States, especially if Mr. Trump won the election.

A proud leftist and a scientist by training, Ms. Sheinbaum had little foreign policy experience in her previous post as mayor of Mexico City. Unlike her predecessor, Andrés Manuel López Obrador, who got along with Mr. Trump and shared his bombastic style, Ms. Sheinbaum was seen more as a reserved technocrat than a political show woman.

But she has surprised many in her country not only by fending off a barrage of threats from Mr. Trump, but also by forging, somewhat improbably, a relationship of budding public respect with her American counterpart.

“Nobody expected her to be this good, or this lucky,” said Carlos Bravo Regidor, a Mexican political analyst. “Whatever it is, it’s working.”

On the campaign trail, Mr. Trump made Mexico a clear target of his attacks. Once elected, he vowed to impose tariffs on America’s southern neighbor until fentanyl stopped flowing into the United States.

Yet lately, he has been lavishing praise on Ms. Sheinbaum, even as he excoriates more seasoned world leaders. He’s called her “a wonderful woman” with whom he has a “very good” relationship.

Her calm demeanor and the results she’s delivered on migration and fentanyl seem to have won his respect, officials from both countries say, impressing key members of his administration, including deputy chief of staff Stephen Miller, who has oversight of domestic policy and is a homeland security adviser.

Her rapport with the American president is helped in part by the contrast with Mr. Trump’s much more contentious relationship with Prime Minister Justin Trudeau of Canada, who is leaving the post on Friday.

At the start of their most recent conversation last week, Ms. Sheinbaum spent about five minutes ticking through everything she had done to secure the border and fight fentanyl trafficking, according to two people familiar with the talks. Ahead of the call, she had sent Mr. Trump data to back up her points. She suggested that the tariffs would only make it harder for her to explain this level of cooperation to her citizens.

Mr. Trump stayed silent for a long beat after she stopped talking — and then, after complimenting Ms. Sheinbaum, abruptly launched into an attack on Canada, the people said. He asked what Ms. Sheinbaum thought of Mr. Trudeau. She said she didn’t talk much with the Canadian leader. Mr. Trump said she was lucky.

At the end of the call, the people said, Mr. Trump offered to exclude many Mexican goods from tariffs and then started dictating, out loud, a Truth Social post announcing the deal. Ms. Sheinbaum and her team were elated.

Mr. Trump posted that he was delaying tariffs until April 2 “out of respect” for the Mexican president, adding: “Thank you to President Sheinbaum for your hard work and cooperation!” Ms. Sheinbaum said the call was “excellent and respectful” in a post on X.

She has also made bold moves against drug cartels known for exacting revenge on those who threaten them. Perhaps the most drastic: the transfer of 29 drug lords to the United States to face criminal charges in late February. That move was a colossal blow to organized criminal groups and sent a message that Ms. Sheinbaum was serious about combating them.

Soon after the handover, Ms. Sheinbaum’s cellphone was hacked, according to several people familiar with the matter. A spokesman for the Mexican presidency declined to comment.

While cooperating intensely with Mr. Trump, Ms. Sheinbaum has also drummed up nationalist sentiment at home, reminding Mexicans that the country is “not a colony of anyone,” and repeating some version of the phrase “coordination, yes; submission, never.”

In recent months, her approval ratings in Mexico have rocketed above 75 percent.

Still, despite Ms. Sheinbaum’s efforts, Mexico hasn’t been shielded from Mr. Trump’s unpredictability. Like the rest of the world, the country awaits another round of potential tariffs on April 2. It’s also contending with steel and aluminum tariffs imposed this week, as well as duties on goods not included in the United States-Mexico-Canada Agreement, which were about half of the country’s U.S. exports last year, according to a White House official not authorized to speak publicly. The trade disruptions have already rattled the Mexican economy.

But as Mr. Trump continues to hammer Canada with new threats of steep levies and annexation, Mexicans are mostly enjoying a break from the drama — at least for now.

“This is like a real life episode of ‘The Apprentice,’” said Mr. Bravo Regidor, referring to the 2000s reality series starring Mr. Trump. “The purpose of the whole show is to survive until the next episode, and she has been able to do that so far.”

The two leaders have come a long way in just a few months.

Mr. Trump has charged that Mexico is run by cartels and threatened military strikes on Mexican soil. And while Mr. Trump often publicly said he had a terrific relationship with Ms. Sheinbaum’s predecessor and mentor, Mr. López Obrador, he also harbored concerns about the former Mexican leader’s management of cartel violence.

Mr. Trump and some key members of his team were initially skeptical of Ms. Sheinbaum, two people familiar with his thinking said, in part because of media coverage that portrayed her as an ideologically committed leftist.

Early on, her rhetoric toward Mr. Trump was at times adversarial.

At a news conference in November, she read aloud a sharply worded letter she had written Mr. Trump responding to his threat of tariffs. “For every tariff, there will be a response in kind, until we put at risk our shared enterprises,” she said.

The missive was viewed by some members of Mr. Trump’s transition team as scolding and an unnecessary provocation, according to five people familiar with their thinking.

Then, in early January, after Mr. Trump said he would rename the Gulf of Mexico the Gulf of America, Ms. Sheinbaum joked that the United States be renamed “Mexican America.” The comments were widely interpreted as poking fun at Mr. Trump.

But her style started to shift as some of her advisers began hearing that confrontational tactics would only anger Mr. Trump.

She won points by deciding to speak to Mr. Trump in English on their calls, three people familiar with talks said. Mr. López Obrador spoke to Mr. Trump in Spanish, through an interpreter, and talked for such a long time that he often bored the president, officials said.

By contrast, Ms. Sheinbaum has come to her conversations with the president extremely prepared, three U.S. and Mexican officials said. She has studied his speeches, watching the videos, to try to understand Mr. Trump’s communication style.

Her tone with him has been calm, and she has come across to officials as serious and transparent. That even-keeled approach has made an impression particularly because it’s so different from that of Mr. Trudeau, who has had more contentious exchanges with Mr. Trump.

Mexico observers pointed to the escalating spat between the United States and Canada as a sign that perhaps Ms. Sheinbaum’s lighter touch with Mr. Trump has shielded the country from further disruptions.

“She has been dignified and discreet in not picking a fight,” said Enrique Krauze, a prominent Mexican historian. “Her natural characteristics have worked well, for now, in the face of a personality like Trump.”

Maria Abi-Habib contributed reporting.

Emily Soriano was doing laundry this week when a friend rushed into her house with news about their yearslong quest for justice.

In December 2016, gunmen stormed into a house in their poor neighborhood north of Manila and started shooting. They killed seven people, including three children and a pregnant woman. Ms. Soriano and her friend, Isabelita Espinosa, each lost a son, both teenagers.

To the victims’ families, the massacre seemed senseless, like thousands of other extrajudicial killings carried out during former President Rodrigo Duterte’s so-called war on drugs. Ms. Soriano and Ms. Espinosa have long held him responsible for the deaths of their sons —Angelito Soriano, 15, and Sonny Espinosa,16 — whom they say were innocent.

Mr. Duterte’s arrest on Tuesday, on accusations of crimes against humanity, was a major milestone toward accountability, the women said.

“What matters to me now is that justice is served,” Ms. Espinosa said. “And that we don’t allow these butchers and tyrants to remain in power. We must fight back.”

While he was in office, Mr. Duterte publicly encouraged the violence, which rights group say left tens of thousands dead. He promised immunity to the police officers who targeted people whom the authorities described as only “drug suspects.” Many were also killed by vigilantes.

Mr. Duterte rose to the presidency campaigning on his law-and-order credentials. He began his deadly antidrug campaign in the city of Davao, where he was the mayor for years and is accused of running a so-called death squad.

Between 2001 and 2007, Clarita Alia said four of her sons — all teenagers accused of petty crimes — were killed at Mr. Duterte’s behest. Over the past two decades, she became a symbol of protest against the killings in Davao, where speaking against Mr. Duterte was once unthinkable.

“I’m happy that he’s been jailed,” Ms. Alia said. “Now, he will feel what the people he hurt felt.”

Mr. Duterte was arrested in Manila on Tuesday after the International Criminal Court issued a warrant accusing him of crimes against humanity. Hours later, he was flown to The Hague, where both the I.C.C. and its detention facilities are based.

He is expected to make his first appearance in court on Friday, according to a court official. But his trial is not expected to start for months.

In the warrant, three judges of the court wrote that they had been presented with evidence that led them to believe Mr. Duterte was personally responsible for the killings and the attacks that were “both widespread and systematic.”

Mr. Duterte has argued the I.C.C. has no jurisdiction in the Philippines because he withdrew his country from the court while he was president. But in the warrant, the judges wrote that they were looking at extrajudicial killings while Manila was a member of the court. His supporters have denounced his arrest and handover to the I.C.C. as political persecution by the current president, Ferdinand R. Marcos Jr. Mr. Marcos has said he was complying with Interpol, which posted the I.C.C. warrant.

In Davao, Mr. Duterte’s stronghold, red ribbons calling for the return of Mr. Duterte were on display in many parts of the city. Some residents had stuck his photos on their vehicles in a show of support.

Ronald Camino said only criminals were angry with Mr. Duterte. “Those who do good are the ones being arrested,” he said.

In the Manila region, Ms. Espinosa got the news of Mr. Duterte’s arrest in a text message. Soon, she and Ms. Soriano were knocking on neighbors’ doors and gathering relatives of other drug war victims. Six other women joined them and hundreds of others that afternoon and lit candles to mark the arrest of Mr. Duterte.

During that rally, in nearby Quezon City, Ms. Espinosa wept for her son.

Ms. Soriano said she shares a birthday with Mr. Duterte, who will turn 80 on March 28. “I want to tell him: ‘I’m happy, this is a gift for me. But for you, it’s bad luck because you’ll be celebrating your birthday in jail.’”

But some Filipinos struggled to process their emotions.

Rodrigo Baylon’s son Lenin was killed by a stray bullet during a shootout in Caloocan in 2016, three days before he turned 10.

Celebrating Mr. Duterte’s arrest, Mr. Baylon said, also meant reliving that horrific event. At the time, Mr. Duterte’s chief of police, Ronald Dela Rosa, who is now a senator, dismissed Lenin’s death as collateral damage in the drug war.

“Is this what they call justice?” Mr. Baylon said. “And will justice really come from the I.C.C.?”

He questioned why a foreign court, not the Philippine government, was holding Mr. Duterte accountable.

“Isn’t the government supposed to help people like us?” Mr. Baylon said.

Marlise Simons contributed reporting from Paris.