European leaders have said "now is a critical moment" to ramp up support for Ukraine and put pressure on Russia to bring an end to the war.

Ukrainian President Volodymyr Zelensky met UK Prime Minister Keir Starmer, French President Emmanuel Macron and German Chancellor Friedrich Merz in London on Monday to discuss the latest version of a peace plan, drafted between Ukrainian and US officials last week.

The European leaders said more work was needed to obtain security guarantees for Ukraine, as the US puts pressure on Kyiv to agree a swift deal with Russia.

Zelensky, who travelled on to Brussels to meet Nato officials, said that Ukraine would share a revised plan with the US on Tuesday.

Last week, Ukrainian officials spent three days with the US negotiating team in Florida pushing for changes to a US-backed peace proposal which has been widely considered favourable to Russia.

Answering questions from journalists after Monday's meeting in London, Zelensky said that the "most certainly anti-Ukrainian points have been removed" from the initial deal proposed in November.

But the Ukrainian president acknowledged that there were some outstanding concerns about ceding territory and a compromise had "not yet been found there".

The US has proposed that Ukraine pull its forces entirely out of eastern regions, which Russia has attempted to take by force, but has been unable to capture in full. In return, the US says Russia would withdraw elsewhere, and there would be a cessation of fighting.

But this is an unpalatable option for Zelensky, who refuses to reward Moscow for its aggression and who has repeatedly warned that Russia would use any foothold in the eastern regions to launch future assaults on Ukraine.

"Americans are inclined, in principle, to finding a compromise," Zelensky said on Monday.

He added that the issue of security guarantees - which Ukraine wants to ensure Russia would be deterred from carrying out future attacks in the event of a peace deal - had yet to be resolved.

A spokesperson for the UK prime minister's office said: "The leaders all agreed that now is a critical moment and that we must continue to ramp up support to Ukraine and economic pressure on Putin to bring an end to this barbaric war.

"The leaders discussed the importance of the US-led peace talks for European security and supported the progress made," the statement said.

Leaders also "underscored the need for a just and lasting peace in Ukraine, which includes robust security guarantees", it added.

Ahead of the talks he hosted at Downing Street, Starmer said there needed to be "hard-edged security guarantees" in a peace deal for Ukraine.

Merz stated he was "sceptical" about some of the details of the potential plan coming from the US side. "But we have to talk about it. That's why we are here," he added.

Following the meeting, France said work would be "intensified" to provide security guarantees for Ukraine.

There is nervousness in Kyiv and across Europe that the US could end its support of Ukraine over frustration with the slow progress of negotiations. "We can't manage without Americans, we can't manage without Europe and that is why we need to make some important decisions," Zelensky said in London.

Although the White House has been pushing Kyiv and Moscow to swiftly agree to a multi-point plan to end the war, there has been little sign of a breakthrough.

A five-hour meeting between US envoy Steve Witkoff and Russian President Vladimir Putin in Moscow last week failed to yield tangible results.

Those talks were followed by three days of discussions between Zelensky's chief negotiator, Rustem Umerov and his US counterparts in Miami, which resulted in vague but positive statements of "progress" from both sides.

However, on Sunday, Trump accused Zelensky of not having read the draft of the revised deal.

"I'm a little disappointed that President Zelensky hasn't yet read the proposal," he said, while insisting Russia's Vladimir Putin was "fine with it".

Almost simultaneously, Zelensky stated that he expected to be briefed on the negotiations by Umerov either in London or Brussels on Monday. "Some issues can only be discussed in person," he said.

The talks in London were the latest attempt by Ukraine's European allies to carve out a role in the US-led efforts to end the war, which they fear will undercut the long-term interests of the continent in favour of a quick resolution.

Despite significant economic pressure and sustained battlefield losses, the Kremlin has shown little sign that it is willing to compromise on its key demands, including ruling out any future path to Ukraine joining the NATO military alliance.

Last week, Putin also restated his willingness to continue fighting until his forces take full control of the Donetsk and Luhansk regions, 85% of which is currently occupied by the Russian army.

As talks in the US and Europe continue, so does the war.

Between Sunday and Monday, a total of 10 people were killed, and 47 were injured as Russian forces attacked nine regions using drones, glide bombs and missiles.

Russia's full-scale invasion of Ukraine began in February 2022. Since then, thousands of civilians and soldiers have been killed or injured, with Ukraine's cities continuing to come under fire on a near-nightly basis.