UKRAINE "must be at the heart" of any negotiations to end the war, Sir Keir Starmer demanded today.
The PM warned Donald Trump that Britain won't support talks about a ceasefire that ice out Kyiv.
And Downing Street admitted that in the face of a new world order where the US cannot be relied on for security - all Europen leaders must bolster their armies.
Ahead of a meeting at the Munich Security Conference between US Vice President JD Vance and Volodymyr Zelenskyy, Sir Keir said: "Nobody wants the conflict to continue and Ukrainians - more than anybody - want the conflict to end, but we must make sure Ukraine is at the heart of this.
"There can't be negotiations around Ukraine without Ukraine being at the heart of it."
In Buckinghamshire the PM added: "It's really important that Ukraine is in the strongest possible position, whether that's in discussions, or whether it's continued fighting."
Trump sparked fear and fury among European leaders this week after announcing that he will hold direct negotiations with Putin on a deal to end the war.
The US President said in-person talks with Putin will take place in Saudi Arabia "in the near future".
In Munich, British Defence Secretary John Healey reiterated that "there can be no negotiation about Ukraine without Ukraine".
But US Defence Secretary Pete Hegseth insisted a final deal would not include NATO membership for Ukraine or the return of Crimea, which was taken by Russia in 2014.
Mr Hegseth sent shock waves across Europe as he added that the US cannot guarantee the continent's security - a dramatic shift in American foreign policy.
Responding to the changing international relations landscape, a No10 spokesperson said: "I think all European leaders agree that Europe needs to step up in terms of defence collaboration, defence spending.
"You can see that in the UK with the increased defence spending that we announced at the budget, our commitment to setting our path to 2.5% of GDP in defence, our work as part of the strategic defence review to determine the challenges, threats and opportunities that UK faces."
Downing Street still hasn't set out a path to spending 2.5 per cent of GDP on defence.
Commons Defence Committee chair Tan Dhesi cautioned that "Europe will now have to play a greater role in the defence of Ukraine and in guaranteeing Ukraine's security".
He said: "We count on the UK Government to show leadership in this. If we don't support Ukraine, Russia will be emboldened."
