Keir Starmer has warned that the UK must be prepared to "defend peace" in Ukraine or conflict will "wash up on our shores".

The Prime Minister unveiled plans to set up a "coalition of the willing" to defend Ukraine and to guarantee peace, backed with British "boots on the ground and planes in the air". But he said it must have "strong US backing".

And he warned: "If you want to preserve the peace, you have to be prepared to defend the peace. The one thing history tells us is if there is conflict in Europe it will wash up on our shores."

Mr Starmer used a press conference to announce that Ukraine will be given £1.6billion of UK export finance to buy 5,000 air defence missiles, which will be made in Belfast. He said the West is "at a crossroads in history today" and warned it is "not a moment for more talk, it is time to act".

Leaders agreed to keep military aid flowing and to turn the screws on Russia's economy, the PM said. Ukraine must have a seat at the table for peace talks, and any deal must guarantee its sovereignty and security.

Ukrainian President Volodymyr Zelensky joined Mr Starmer and 17 other leaders and representatives for an emergency summit in London before heading to Sandringham to meet the King. The unusual show of solidary came less than 48 hours after he faced a sickening diatribe from US President Donald Trump and sidekick JD Vance.

Mr Starmer told journalists: "I do not accept that the US has become an unreliable ally." He said leaders in France, Britain and Ukraine are drawing up a peace plan, which will be presented to Mr Trump.

The conference at Lancaster House was held to "unite our partners" behind the plan, he said.

It came after European and NATO allies gathered in London for an emergency summit amid growing alarm about Donald Trump's commitment to defending Europe.

Earlier the Prime Minister said he felt "uncomfortable" watching Friday's clash between the US President and Mr Zelensky in the Oval Office. But he said he responded by "rolling up my sleeves" and talking to both sides rather than voicing outrage on social media.

The Prime Minister told the BBC's Laura Kuenssberg: "Yes, I felt uncomfortable. Nobody wants to see that. But the important thing is how to react to that.

"There are a number of different routes people could go down. One is to ramp up the rhetoric as to how outraged they are... The other is to do what I did, which is roll up our sleeves, pick up the phone."

Asked whether he still trusts Trump, Mr Starmer said: "Yes, I do." He continued: "I have had extensive discussions with him and I believe his motivation is lasting peace."

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But he doubled down on his demand for a US security guarantee if a peace deal is secured to end the war in Ukraine. Responding to a question about Russian tyrant Vladimir Putin he said: "Well, no, I wouldn't trust Putin, which is why I want a security guarantee (from the US). I wouldn't trust him not to come again, because he's proven that he will come again.

"He's already done it and we know what his ambitions are." There is growing anxiety across Europe following Mr Trump's derisory treatment of the Ukrainian leader.

Even before the exchange, the US President had raised alarm by opening talks with Russia last month without Mr Zelensky being present. And he is yet to commit to a security guarantee to prevent Putin striking again in the future.

This has led to a perception that the US will not take a tough line with the Russian tyrant, sparking fears for Europe's security. Following Friday's exchange at the White House, EU foreign policy chief Kaja Kallas said: “Today, it became clear that the free world needs a new leader. It’s up to us, Europeans, to take this challenge.”