NATO chief Mark Rutte has warned that it is vital for the future of European security that the US and Ukrainian presidents are back on speaking terms ahead of a crucial summit in London

Ahead of a pivotal summit in London, Volodymyr Zelensky, the Ukrainian president, has received a significant warning from NATO’s head.

The meeting of European leaders, hosted by Keir Starmer at Lancaster House on Sunday, comes as efforts to establish peace in Ukraine continue.

This follows a shocking outburst by Donald Trump in the White House 48 hours ago, which left many fearing that the US had abandoned its allies.

Last night, Mr Starmer warmly welcomed Zelensky at Number 10 and is believed to have contacted Trump afterwards in an attempt to mend their relationship ahead of a potential second White House meeting, although nothing has been agreed upon yet.

Mark Rutte, the Secretary General of NATO who will also be present at today’s meeting, emphasised the importance of restoring the relationship between the US and Ukrainian presidents for the future of European security.

He told the BBC: “It is important that President Zelensky finds a way to restore his relationship with the American President and with the senior American leadership team”.

At Lancaster House, the Prime Minister is expected to encourage the leaders of 18 European countries to follow the UK’s lead in responding to the US’s calls for increased defence spending.

Keir Starmer stated that he is “working hard” to achieve lasting peace in Ukraine and that his “driving purpose” over the past few days has been to reconcile Ukraine and the US following their disagreement in the Oval Office.

The Prime Minister shared his discomfort with BBC’s Laura Kuenssberg, saying he felt “uncomfortable” watching the meeting between Trump and Zelensky live from Number 10, adding: “Nobody wants to see that.”

He detailed his proactive approach to mending fences, stating: “The important thing is how to react to that. There are a number of different routes people could go down.

“One is to ramp up the rhetoric as to how outraged we all are or not. The other is to do what I did, which is roll up my sleeves, pick up the phone, talk to President Trump, talk to President Zelensky, then invite President Zelensky for an extensive meeting yesterday, a warm welcome, and then further pick up the phone to President Macron and President Trump afterwards.

“My driving purpose has been to bridge this, if you like, and get us back to the central focus.”

Meanwhile, Russian Foreign Minister Sergey Lavrov commended Donald Trump in an interview with military newspaper Krasnaya Zvezda, saying it was “interesting to work with him”.

However, he also issued a stark warning against the idea of a cross-European peacekeeping force, arguing it would merely serve to support President Zelensky with “bayonets” and adversely affect Russian speakers in Ukraine.