Sir Keir Starmer has challenged Donald Trump’s Ukraine peace plan by insisting Crimea must not be handed to Russia and demanding that Kyiv, not Washington, take the lead in negotiations. The Prime Minister's stance sets him on a collision course with Mr Trump, who has floated the possibility of recognising Crimea as Russian and blamed President Volodymyr Zelensky for “prolonging the killing”.

Speaking aboard HMS Prince of Wales, the Prime Minister said: “It is Ukraine that must decide on those issues – it’s not for other people to decide on behalf of Ukraine. Russia must come to the table for that unconditional ceasefire.” Sir Keir bluntly rejected any suggestion that Mr Zelensky was responsible for the lack of a deal. He said: “Russia is the aggressor. Never forget that Zelensky was offered safe passage out of his country in the first week of the conflict…and he stayed to fight and to lead his country with huge courage and resilience.”

He also warned against any settlement that left Russia in a position to rearm and strike again, adding: “I don’t want to see a ceasefire that is temporary. I’m convinced that will simply leave Russia with the capability to come again.”

In marked contrast to Mr Trump’s reported willingness to offer concessions, Sir Keir maintained that any deal must be “rooted in international law, not capitulation.”

Mr Zelensky has insisted his five-point plan – which rejects any recognition of Russian sovereignty over Crimea – is now “on President Trump’s desk.”

Sir Keir’s comments come amid signs of a rift between London and Washington over the deal’s wording.

UK officials are privately lobbying for amendments to avoid undermining Kyiv – and risking another Russian offensive.

Speaking in the White House cabinet room on Thursday, US President offered a clear indication of his rising frustration at the situation.

He said: "I have my own deadline".

"I'm saying we can save thousands of people, and I don't like that it takes long at all.

"But I think they both want to make peace.

"I do believe so, there's a lot of hatred there, there's a lot of very bad blood.”

Just a few hours earlier, Mr Trump had pleaded with Vladimir Putin in a Truth Social post to "stop" the war and the attacks on Ukraine, referring to the Russian leader by his first name.

Yesterday, Mr Trump also accused Mr Zelensky of "inflammatory statements", after the Ukrainian leader said giving away Crimea "violates" his country's constitution.