Sir Keir Starmer has said peace “must be built with Ukraine, not imposed upon it”, amid concerns Kyiv will be excluded from talks between Donald Trump and Vladimir Putin.
The US president and his Russian counterpart are set to meet in Alaska this week to discuss the future of the Kremlin’s invasion.
In a phone call on Monday with Mark Carney, the Prime Minister and Canada’s leader agreed Ukraine’s future “must be one of freedom, sovereignty and self-determination”.
It comes after Mr Trump signalled he thinks Ukraine might need to cede territory in order to end the conflict.
A Downing Street spokesperson said: “The Prime Minister spoke to the prime minister of Canada Mark Carney this afternoon.
“They discussed their unwavering support for Ukraine and ongoing work to stop the killing, and end Russia’s war of aggression.
“Both leaders underscored that Ukraine’s future must be one of freedom, sovereignty and self-determination.
“They welcomed continued international efforts, led by President Trump, to bring peace and agreed that this must be built with Ukraine, not imposed upon it.
“Both leaders agreed they would continue to work closely with President Trump and President Zelensky over the coming days. They agreed to stay in touch.”
Earlier on Monday, No 10 had backed Mr Trump’s interventions over the war but warned that Mr Putin cannot be trusted “as far as you can throw him”.
Asked whether Sir Keir believes the Russian president could be trusted in negotiations, the Prime Minister’s official spokesman said the UK supported both Kyiv and the US president’s push for peace, but not Moscow.
“Never trust President Putin as far as you could throw him, but we obviously will support Ukraine,” he said.
“We will obviously support President Trump and European nations as we enter these negotiations.
“But it is exactly why we’ve been leading this work on the coalition of the willing, because any ceasefire, as I say, cannot just be an opportunity for President Putin to go away, re-arm, restrengthen, and then go again.
“So we’re not going to leave it to trust. We’re going to ensure that we’re prepared such that we achieve a ceasefire.”
Planning for the so-called coalition of the willing, which would involve a European-led peacekeeping force sent to Ukraine to monitor any future truce, began in March.
Downing Street said “operational planning continues at a military level” despite no talks between leaders planned for this week, but indicated that there was little left to finalise.
Another week has ended without any attempt by Russia to agree to the numerous demands of the world and stop the killings. In just the past 24 hours on the front, there have been 137 combat engagements, and this is the case every day. The Russian army is not reducing its pressure.… pic.twitter.com/FcpEOTiIXW
— Volodymyr Zelenskyy / Володимир Зеленський (@ZelenskyyUa) August 11, 2025
Asked whether work relating to the coalition had been put on hold to keep the road clear for Washington-led mediation this week, the Prime Minister’s spokesman said: “No… if anything, the next step really is reaching that ceasefire, such that we’re then able to implement the security guarantees.”
European leaders including Sir Keir said the path to peace for Kyiv “cannot be decided without Ukraine” and the current line of contact between Russia and Ukraine could only be a “starting point of negotiations”.
In a joint statement, the leaders of Britain, France, Italy, Germany, Poland, Finland and the European Commission said: “Ukraine has the freedom of choice over its own destiny.
“Meaningful negotiations can only take place in the context of a ceasefire or reduction of hostilities.
“The path to peace in Ukraine cannot be decided without Ukraine.
“We remain committed to the principle that international borders must not be changed by force.”
The statement comes a day after Mr Trump announced that he would meet Mr Putin in Alaska on Friday, as he seeks an end to a conflict he had promised he could finish on his first day in office.
The US president had earlier suggested that any peace deal was likely to involve “some swapping of territories”, with reports suggesting this could involve Ukraine giving up its Donetsk region.
But President Volodymyr Zelensky has already rejected any proposal that would compromise Ukraine’s territorial integrity, something that is forbidden by Ukraine’s constitution.
He said Mr Putin wanted to “exchange a pause in the war, in the killing, for the legalisation of the occupation of our land – he wants to get territorial spoils for the second time”.
Mr Zelensky added: “We will not allow this second attempt to partition Ukraine.
“Knowing Russia, where there is a second, there will be a third.”
