Keir Starmer has said he is ready to put British “boots on the ground” to maintain the peace if a deal is done to end the war in Ukraine.

The prime minister said he was working with French president Emmanuel Macron to come up with a plan to present to Donald Trump aimed at finally ending the three-year-long conflict.

He was speaking after hosting an emergency summit of world leaders at Lancaster House in London at which he also set out his plan to build a “coalition of the willing” to deter Russia from attacking its neighbour again.

Ukrainian president Volodymyr Zelenskyy also attended the gathering in a show of European unity following his extraordinary bust-up with Trump in the White House on Friday.

Starmer said Europe was “doubling down in our support” of Ukraine as he announced that Britain would donate a further £1.6 billion in export finance to the country so it can by 5,000 air defence missiles to be made in Belfast.

The PM said: “We are at a crossroads in history. This is not a moment for more talk, it is time to act, time to step up and lead and unite around a new plan for a just and enduring peace.”

Declaring that any peace deal “must be backed by strength”, Starmer said: “We will go further to develop a coalition of the willing to defend a deal in Ukraine and to guarantee the peace.

“Not every nation will feel able to contribute but that can’t mean that we sit back. Instead, those willing will intensify planning now with real urgency.

“The UK is prepared to back this with boots on the ground and planes in the air, together with others. Europe must do the heavy lifting.”

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