European leaders raced on Sunday to salvage Ukraine’s ruptured relationship with the United States, with Britain and France assembling a “coalition of the willing” to develop a plan for ending Ukraine’s war with Russia. They hope this effort will win the backing of a skeptical President Trump.
Gathering in London at the invitation of Prime Minister Keir Starmer of Britain, the leaders vowed to bolster support for President Volodymyr Zelensky of Ukraine after his bitter clash with Mr. Trump last week. But several also expressed hope that the two could repair their breach, underscoring Europe’s reluctance to cast off a trans-Atlantic alliance that has kept the peace for 80 years.
“We are at a crossroads in history,” Mr. Starmer said after the meeting. “Europe must do the heavy lifting,” he declared, but added, “To support peace, and to succeed, this effort must have strong U.S. backing.”
Mr. Starmer said he believed that despite Mr. Trump’s anger toward Mr. Zelensky in the Oval Office on Friday, Mr. Trump was committed to a lasting peace agreement between Ukraine and Russia. He said Britain and France, working with other European countries, would develop their own plan with Mr. Zelensky.
Details of the plan were sketchy, but Mr. Starmer suggested that the Europeans could use it as a basis to persuade Mr. Trump to commit to American security guarantees. Britain and France have already pledged to contribute troops to a peacekeeping force and are trying to enlist other countries across Europe.
“I wouldn’t be taking this step down this road if I didn’t think it would yield a positive outcome in terms of ensuring that we move together,” Mr. Starmer said, referring to Mr. Trump.
His comments captured the dilemma confronting Europe two weeks after Mr. Trump’s surprise overture to President Vladimir V. Putin of Russia. Neither Europe nor Ukraine currently has seats at the table in a potential Trump-brokered peace deal. Nor has Mr. Trump agreed to give any security assurances to prevent Russia from launching another invasion of its neighbor.
Mr. Trump’s acrimonious exchange with Mr. Zelensky deepened the divide. “Nobody wanted to see what happened last Friday,” said Mr. Starmer, who had his own, much smoother meeting with Mr. Trump a day earlier.
The prime minister has tried to mediate between Mr. Zelensky and Mr. Trump. Speaking to both men by phone after their clash, he floated the idea of Mr. Zelensky’s returning to the White House on Friday evening to mend fences with the president, according to a senior British official.
Both leaders demurred, saying it would be better to let tempers cool and the air to clear, according to the official, who spoke on the condition of anonymity because of the delicacy of the issue. Still, Mr. Zelensky has also expressed a belief that his rift with Mr. Trump is not irreparable.
On Sunday in London, Europe wrapped Mr. Zelensky in a warm embrace. He won gestures of support from the 18 assembled leaders, including President Emmanuel Macron of France, Chancellor Olaf Scholz of Germany, Prime Minister Giorgia Meloni of Italy and Prime Minister Justin Trudeau of Canada.
Afterward, Mr. Zelensky flew to meet King Charles III at his country estate, Sandringham, northeast of London. That visit, at the request of Mr. Zelensky, had a symbolic resonance, since Mr. Starmer had hand-delivered a rare invitation to Mr. Trump from the king to make a second state visit to Britain.
Yet behind the choreographed show of solidarity, there was a recognition that keeping the United States on board remains critical.
“Starmer has two goals,” said Mujtaba Rahman, an analyst at the political risk consultancy Eurasia Group. “Build an offer with the Ukrainians and Europeans that keeps the U.S. positively engaged in Ukraine’s security, while simultaneously preparing for a worst-case scenario where that may not prove possible.”
That will require European countries to shoulder a much heavier burden in the continent’s defense. Mr. Starmer pushed leaders to follow Britain in bolstering its military spending. Mark Rutte, the secretary general of NATO, said several countries had pledged to do so, though he declined to name them.
On Saturday, after meeting Mr. Zelensky, Mr. Starmer gave Ukraine a loan of 2.26 billion pounds (about $2.8 billion) to buy military hardware. On Sunday, he announced plans to allow Ukraine to use 1.6 billion pounds ($2 billion) in British export financing to buy more than 5,000 advanced air defense missiles.
The president of the European Commission, Ursula von der Leyen, said the European Union would fortify Ukraine with economic and military aid, aiming to turn it into “a steel porcupine that is indigestible for potential invaders.”
The Ukraine war has thrust Mr. Starmer into an unaccustomed place for a British prime minister: the heart of Europe, during a crisis. More than eight years after the country voted to leave the European Union, the rapidly changing security landscape is driving Britain closer to the continent.
Catherine Ashton, a Briton who served as the bloc’s high representative for foreign affairs and security policy, said Mr. Starmer’s successful meeting with Mr. Trump had reinforced his credentials as a leader for Europe.
“It is unsurprising that allies in Europe are gathering in London this weekend and equally unsurprising that the U.K. is being taken much more seriously in Brussels and capitals,” Ms. Ashton said.
And yet there are limits to Mr. Starmer’s diplomacy. He was unable to extract security guarantees from Mr. Trump, despite an exaggerated show of deference to the president that included the invitation from the king.
For Mr. Starmer, the crisis is an opportunity to draw closer to Europe. He has long wanted to do that on the trade front but has approached it gingerly because of the political sensitivities at home. The Labour Party does not want to lose its core working-class voters, many of whom favored Brexit, to the anti-immigration party, Reform U.K., which is led by Nigel Farage.
But boosting military spending is popular with Reform voters. Standing behind Ukraine and against Russian aggression also puts Mr. Farage, with his history of sympathy for Mr. Putin, in a tricky position.
Whether that will allow Mr. Starmer to reintegrate Britain’s economy and trade with that of the European Union is another question. Some analysts noted that the E.U. was in no rush to overhaul its existing trade agreement with Britain, which it views as beneficial to the continent. Mr. Starmer’s political fortunes still depend on his government’s turning around Britain’s ailing economy.
“The country is in such a dire state that I don’t think Starmer will be rewarded for being an international statesman,” said Mr. Rahman, the analyst. “It’s an arguably dangerous thing for a prime minister to try to build political capital abroad when the domestic agenda isn’t moving in the direction he wants.”
Mr. Starmer’s use of the phrase “coalition of the willing” had a disquieting echo of President George W. Bush in the lead-up to the Iraq war. Britain, under a Labour prime minister, Tony Blair, joined the United States, but France and Germany did not.
The shock of Mr. Trump’s statements about Russia and Ukraine could reduce such divisions this time around, diplomats said.
“People realize they can no longer count on a nice Russia and a generous America, and that they have to get their act together on a number of issues, including defense and security,” said João Vale de Almeida, a former E.U. ambassador to the United States and Britain. The British, he said, are “more European than American in terms of what unites them to Europe and what unites them to America.”
Still, Mr. Starmer, who said he discussed his plans with Mr. Trump on Saturday night, rejected suggestions that the trans-Atlantic alliance was finished. “I do not accept that the U.S. is an unreliable ally,” he said.