Sir Keir Starmer has emphasised Britain's unflinching support for Ukraine after it emerged Volodymyr Zelensky had proposed an ultimatum for ending the bloodshed.

He stressed to European allies that any peace must be 'just and lasting' - as all eyes turn to an imminent crunch summit in Florida between Zelensky and President Trump.

In a call with German and French leaders on Friday, the Prime Minister said it remained 'a crucial moment for Ukraine and security across the Euro-Atlantic region', as all three reaffirmed their 'unwavering commitment' to Ukraine.

A Downing Street spokesperson said the leaders 'reiterated their unshakeable commitment for a just and lasting peace for Ukraine and the importance that talks continue to progress towards this in the coming days'.

The leaders spoke after Mr Zelensky declared on Friday morning that he was planning a last-minute trip to meet Trump in Florida, in hopes of negotiating a peace deal before the New Year.

He confirmed that he would be open to letting the people decide Ukraine's fate, by putting the latest version of the peace plan to a referendum if the Kremlin agrees to a ceasefire lasting at least 60 days. 

Mr Zelensky said he would meet Mr Trump in Florida over the weekend to discuss security guarantees, insisting a peace plan is 'about 90 percent ready'.

He added that he expected to discuss an 'economic agreement' and 'territorial issues' with Mr Trump, and said he hoped European leaders could also be involved in talks either on Sunday or at a future date.

President Zelensky will meet President Trump in Florida later his week to finalise the latest version of the peace plan

Russian attacks continue to rain down on Ukraine, inflicting scenes of devastation such as this scene in Odesa on Christmas Day

Sir Keir Starmer has restated Britain's unflinching support for Ukraine

The talks in Florida are the latest stage in Mr Trump's year-long effort to secure a ceasefire in Ukraine, having promised to do so rapidly when he came to power.