Europe must “step up” its defence capabilities to face the “generational” security challenge posed by Russia’s invasion of Ukraine, UK Prime Minister Sir Keir Starmer has said.

His remarks come after he wrote that he was “ready and willing” to put UK troops on the ground in Ukraine to help guarantee its safety in a future peace deal.

Sir Keir arrived in Paris on Monday afternoon for summit of European leaders to discuss concerns over the US-Russia talks on ending the war that will lock out the continent.

US and Russian officials are set to meet in Saudi Arabia on Tuesday, without representatives from Europe or Ukraine attending.

“We need to step up in terms of our collective response in Europe, and by that I mean capability,” Sir Keir said ahead of the meeting at the Élysée Palace.

“By that, I mean playing our full part when it comes to the defence of the sovereignty of Ukraine if there’s a peace agreement.”

The prime minister had earlier written in the Telegraph that he was willing to send soldiers to Ukraine, alongside troops from other European nations, in a peacekeeping role to police the border between Ukrainian-held and Russian-held territory.

But the former head of the British Army, Lord Dannatt, said doing so would come at a “considerable cost” and require an increase in military funding.

The UK currently spends around 2.3% of its total economic output on defence. The government has committed to increasing defence spending to 2.5%, but has not said when this will be achieved.

Sir Keir told reporters that the government would set out a path to meeting the 2.5% commitment once it finishes its strategic defence review.

“Part of my message to our European allies is that we’ve all got to step up on both capability and on spending and funding,” he said.

“That includes the UK, which is why I’ve made that commitment to spend more.”

Sir Keir has joined the leaders of France, Germany, Italy, Poland, Spain, the Netherlands and Denmark, along with the presidents of the European Council and European Commission, and Nato Secretary General Mark Rutte.

The hastily arranged summit was announced over the weekend after Trump administration officials suggested European nations, including Ukraine, would be consulted on peace talks with Russia but not involved directly in them.

Ukrainian President Volodymyr Zelensky has said Kyiv did not know about the talks and would not recognise any agreement made without its involvement.

European leaders have also expressed concern after US Defence Secretary Pete Hegseth said last week that it was “unrealistic” to expect Ukraine will return to its pre-2014 borders – before Russia annexed Crimea and took parts of the nation’s south and east in its 2022 full-scale invasion.

Hegseth also downplayed the prospect of Ukraine joining the mutual defence alliance Nato – something with Sir Keir has said it was on an “irreversible” path towards.

A Downing Street spokesman said the prime minister will tell Monday’s summit Europe must “take on a greater role in Nato” as the Trump administration adopts a less interventionist approach to foreign policy.

Sir Keir will say this requires “further supporting Ukraine’s military” as well as “being ready to contribute to security guarantees by putting our own troops on the ground if necessary”, the spokesman added.

Meanwhile, Polish Prime Minister Donald Tusk has already indicated his nation would not send troops into Ukraine, but would continue to support it with military, financial and humanitarian aid.

Fighting on the ground in Ukraine continued over the weekend, with at least three civilians killed in Russian strikes on Sunday, according to local authorities.

Several areas of Ukraine are under an emergency blackout following attacks on energy infrastructure, while Russia’s defence ministry said it intercepted and destroyed 90 Ukrainian drones on Sunday night.