Tensions between Israel and Iran could dominate discussions among world leaders at the Nato summit amid a fragile ceasefire.
Sir Keir Starmer is among those in The Hague for a gathering of the alliance, having called on the Middle Eastern nations to maintain the pause in hostilities.
In a conversation with the French and German leaders at the summit on Tuesday, Sir Keir “reflected on the volatile situation in the Middle East,” according to a Downing Street spokeswoman.
The leaders agreed that “now was the time for diplomacy and for Iran to come to the negotiating table”, the spokeswoman added.
It comes as intelligence reports in the US suggested that the American attack on Iran’s nuclear programme over the weekend have only set it back by a few months, rather than destroyed it as Donald Trump previously suggested.
The White House pushed back on the reports on Tuesday evening, with press secretary Karoline Leavitt saying it was “flat out wrong”.
“The leaking of this alleged assessment is a clear attempt to demean President Trump, and discredit the brave fighter pilots who conducted a perfectly executed mission to obliterate Iran’s nuclear programme,” she said in a statement.
Mr Trump also condemned the leak in a post on Truth Social, calling the US raid “one of the most successful military strikes in history”.
“THE NUCLEAR SITES IN IRAN ARE COMPLETELY DESTROYED! BOTH THE TIIMES AND CNN ARE GETTING SLAMMED BY THE PUBLIC!” he wrote.
Earlier on Tuesday, Sir Keir had said that the US had helped in “alleviating” the threat of nuclear capability for Iran with their strikes on Saturday.
Asked on his visit to The Hague whether he personally felt safe with Mr Trump in the White House and why others should, the Prime Minister told Channel 5 News: “Look, I think what we’ve seen over the last few days is the Americans alleviating a threat to nuclear weaponry by the Iranians and bringing about a ceasefire in the early hours of today.
“I think now what needs to happen is that ceasefire needs to be maintained, and that will be the focus of our attention, our engagement, our discussions, because that ceasefire provides the space for the negotiations that need to take place.”
After the ceasefire was initially struck early on Tuesday, Israel claimed Iran had violated the deal by carrying out strikes after it came into force.
Mr Trump called for Israel to withdraw its warplanes, and claimed both it and Iran “don’t know what the f*** they’re doing” as he departed for the summit in the Netherlands.
The UK has continued to evacuate Britons out of Israel, and a second flight left Tel Aviv on Tuesday.
The Foreign Office confirmed the plane had left Israel and said further flights would be considered depending on demand.
Meanwhile, the Liberal Democrats have said that MPs should be given a vote in the event of any future deployment of troops.
The party’s foreign affairs spokesman Calum Miller said: “With the Middle East in the throes of an all-out regional war, we are reckoning once again with the prospect of the UK becoming embroiled in foreign conflict.
“No one knows the fragility of peace in that region, or the price paid for our safety, better than our British troops. It’s critical that, if they are asked to put their lives on the line for the UK in active conflict zones, this decision is subject to the strongest democratic scrutiny our country can offer.”
