Foreign Secretary David Lammy warned a deal to end the war in Ukraine was at “a critical moment” as the US said it could “walk away” from talks. Vice-president JD Vance said President Donald Trump could abandon efforts to broker peace unless both Ukraine and Russia agreed to give up territory.

US secretary of state Marco Rubio and Steve Witkoff, Trump’s special envoy, yesterday pulled out of talks in London with Mr Lammy and Defence Secretary John Healey, blaming “scheduling” issues. It was reported they cancelled the trip because Ukraine had refused to sign up to a deal backed by the US that would recognise Russian sovereignty over Crimea, a region of Ukraine seized by Russia during an earlier invasion in 2014.

The proposed agreement would also give Russia control occupied parts of Donetsk, Lukhansk, Kherson and Zaporizhzhia, and would involve Ukraine accepting that it could not join NATO.

Mr Witkoff will instead head to Russia, where he is likely to hold his fourth meeting with President Vladimir Putin.

Speaking to reporters in India, Mr Vance said the President “issued a very explicit proposal to both the Russians and the Ukrainians, and it’s time for them to either say ‘yes’, or for the United States to walk away from this process”.

He said: “That means the Ukrainians and the Russians are both going to have to give up some of the territory they currently own.”

Downing Street put a brave face on the snub and the Prime Minister’s spokesman said the UK remains “absolutely committed” to securing a “just and lasting peace in Ukraine”.

Mr Lammy and Mr Rubio spoke on Tuesday night and agreed further technical talks were needed before the next meeting of ministers, a UK source said.

The Foreign Secretary said: “The UK is working with the US, Ukraine and Europe to put an end to Putin’s illegal invasion.”

Mr Lammy and Mr Healey went ahead yesterday with talks involving Ukrainian foreign minister Andrii Sybiha and defence minister Rustem Umerov, as well as officials from the US and Europe.

Ukrainian President Volodymyr Zelensky said: “Ukraine has repeatedly said that it does not rule out any format that can lead to a ceasefire and, ultimately, real peace.”