“We are all working together in Europe in order to find a basis for cooperation with America for a true peace and guaranteed security,” Zelensky said after the summit.

Meanwhile, French President Emmanuel Macron told Le Figaro newspaper that Paris and London wanted to propose a one-month truce between Russia and Ukraine “in the air, at sea and on energy infrastructure”.

Speaking at a news conference shortly after the meeting of leaders, Starmer said four points had been agreed:

Starmer also announced an additional £1.6bn ($2bn) of UK export finance to buy more than 5,000 air defence missiles. This comes on top of a £2.2bn loan to provide more military aid to Ukraine backed by profits from frozen Russian assets.

“We have to learn from the mistakes of the past, we cannot accept a weak deal which Russia can breach with ease, instead any deal must be backed by strength,” he said.

The prime minister did not state which countries had agreed to join this coalition of the willing, but said that those who had committed would intensify planning with real urgency.

The UK, he said, would back its commitment with “boots on the ground, and planes in the air”.

“Europe must do the heavy lifting,” he said, before adding that the agreement would need US backing and had to include Russia, but that Moscow could not be allowed to dictate terms.

“Let me be clear, we agree with Trump on the urgent need for a durable peace. Now we need to deliver together,” Starmer said.

When asked if the US under Trump was an unreliable ally, he said: “Nobody wanted to see what happened last Friday, but I do not accept that the US is an unreliable ally.”