European leaders reaffirmed their support for Kiev at a summit in London on Sunday, where they committed to increasing defense spending and forming a coalition to safeguard any potential truce in Ukraine.

The gathering of 18 allied nations focused on securing long-term security guarantees for Ukraine and strengthening Europe's defense capabilities while ensuring continued engagement with US President Donald Trump.

Amid lingering concerns over the US commitment to Ukraine and NATO—heightened by a tense public exchange between Trump and Ukrainian President Volodymyr Zelensky—UK Prime Minister Keir Starmer underscored the critical juncture facing Europe.  

"This is not a moment for more talk -- it's time to act. It's time to step up and lead and unite around a new plan for a just and enduring peace," Starmer stressed.  

With US involvement uncertain, Starmer emphasized that "Europe must do the heavy lifting" in securing peace in Ukraine, noting that several nations had expressed willingness to contribute to maintaining stability.  

"Europe must do the heavy lifting, but to support peace in our continent, and to succeed, this effort must have strong US backing," said Starmer, who also announced a deal allowing Ukraine to use £1.6 billion ($2 billion) of UK export finance to buy more than 5,000 air defense missiles.

Zelensky was warmly received by summit attendees, including Starmer, Canadian Prime Minister Justin Trudeau, and NATO Secretary-General Mark Rutte.

This reception stood in stark contrast to Zelensky’s treatment at the White House on Friday, where Trump criticized him for not expressing sufficient gratitude for US aid and accused him of being unprepared for peace with Russia.  

The confrontation, broadcast globally, fueled concerns that Trump aims to pressure Kiev into a settlement that would favor Russia while leaving Ukraine vulnerable.  

'Rearm Europe'

As the summit convened, European Commission President Ursula von der Leyen called for urgent measures to "rearm Europe" and "prepare for the worst."

Von der Leyen said she would present a "comprehensive plan" at an EU summit on Thursday, adding that "we have to have a surge in defence" and "step up massively."

"It's now of utmost importance we increase spending ... it's important we prepare for the worst," she added.

The leaders had a "good and frank discussion" and talked about the need for security guarantees, said the EU chief.

Addressing US President Donald Trump, she said, "We're ready together with you to defend democracy, to defend the principle that there's a rule of law, that you cannot invade your neighbour and bully your neighbour, or you cannot change borders with force."

"It's in our common interest that we prevent future wars," she added.

German Chancellor Olaf Scholz said a halt in fighting could be a starting point for potential peace talks for Ukraine.

"It would be very helpful if the bombing were to stop...That would also be the starting point for talks that can then continue," Scholz told reporters after the meeting.

He said that a focus for allies will be to ensure that Ukraine has a strong army when the war there is over so that it can defend itself against any future aggression.

"The basis of everything will be a strong army," Scholz said.

Polish Prime Minister Donald Tusk, meanwhile, urged Europe and the US to "speak with one voice" in demonstrating to Russian President Vladimir Putin that "the West has no intention of capitulating before his blackmail and aggression."

Starmer and French President Emmanuel Macron reaffirmed their readiness to deploy British and French troops to Ukraine to uphold any peace agreement reached to end the war.

Macron announced after the meeting that France and Britain have proposed a one-month truce in Ukraine, covering both air and sea operations, following emergency talks in London.

In an interview for France's Le Figaro newspaper, Macron also called on European nations to increase their defense spending to between 3.0 and 3.5% of their GDP in response to Washington’s evolving priorities.

"For three years, the Russians have spent 10 percent of their GDP on defence," he stated. "So we have to prepare for what's next."

Starmer, Macron announce 'coalition of the willing'

Starmer and Macron are leading attempts to put together a group of countries who would contribute in different ways to the effort, referred to as a "coalition of the willing."

"A number of countries have indicated today that they want to be part of the plan that we are developing," revealed Starmer, without naming the nations.

Rutte highlighted commitments from additional European nations to "ramp up defence spending," while stressing that the US remained engaged in NATO.

Starmer said he was convinced Trump wanted to see a lasting peace in Ukraine despite the row between the US President and Zelensky on Friday.

Trump has yet to commit to any security guarantees, but Starmer noted that discussions were on the basis "that it will have US backing."

"I would not be taking this step down this road if I didn't think that it was something that would yield a positive outcome in terms of ensuring that we move together, Ukraine, Europe, UK and US," the UK premier said.

Starmer also said during a press conference that the US was "not an unreliable ally," adding, "Nobody wanted to see what happened last Friday, but I do not accept that the US is an unreliable ally."

The summit brought together representatives from across Europe, including France, Germany, Denmark, Italy, Turkiye, NATO, and the European Union.  

Beyond the security discussions, Zelensky also met with King Charles III at Sandringham during his visit to the UK.  

Earlier on Sunday, Zelensky and Starmer announced a £2.26 billion ($2.84 billion) loan package to bolster Ukraine’s defense, to be repaid using profits from frozen Russian sovereign assets.

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