Andy Burnham is expected to meet Donald Trump face-to-face for the first time since entering No 10 in New York next week.
The prime minister is set to travel to New York for the UN general assembly, marking one of his most important trips abroad since taking over from Sir Keir Starmer.
Mr Burnham will reportedly meet the US president on the sidelines of the event, in what will be their first in-person conversation and a major diplomatic moment.
They will likely discuss a number of tense topics, including the UK’s sanctions on illegal Israeli settlements, Ukraine and the war in the Middle East.
Mr Trump has been largely positive about Mr Burnham’s first weeks as prime minister, which comes after relations with his predecessor, Sir Keir Starmer, dramatically deteriorated in the final months of his tenure.
The leaders have spoken twice on the phone since Mr Burnham became prime minister, but have recently been at odds over major issues including the Falkland Islands and Northern Ireland.
During his tenure as the mayor of Manchester, Mr Burnham heavily criticised Mr Trump, insisting he would not be welcome in the city and that he had a “poisonous” politics.
He later climbed down on the comments, telling reporters in August he “tries to find common ground” with other politicians.
“Well, he’s said things as well, and everyone says things as politicians. In the moment you meet people where they’re at, and you find a connection with people, and that’s always been my style,” he said.
Donald TrumpI don't know, I think I see that he was, I guess, the mayor of a town. I hear he's extremely liberal, extremely, so that means he probably won't open up the North Sea
He added that he was “looking forward to meeting in person” and said he had a “good phone call” with the US president on his first day in office.
Shortly before Mr Burnham was confirmed as Britain’s new prime minister, Mr Trump described him as an “extremely liberal” politician who was “mayor of a town”, and "probably won't open up" the North Sea for further oil and gas drilling.
Mr Trump was amongst the first world leaders Mr Burnham spoke to after taking office, with the prime minister having extended an invitation to Manchester to the president, as the pair discussed football, defence and the war in the Middle East.
Mr Trump later claimed the prime minister had pledged to “open up the North Sea” in the phone call.
He said: “He said he's going to open up North Sea oil. If he does that, you're going to be a wealthy country.”
Mr Burnham meanwhile said the first exchange was positive, describing the US president as “really warm”.
Last week, the pair held their second phone call, where they agreed on the need to "continue working towards a ceasefire” in Ukraine, and Mr Burnham briefed Mr Trump on plans to implement a trade ban on imports from illegal Israeli settlements.
Donald TrumpHe said he's going to open up North Sea oil. If he does that, you're going to be a wealthy country.
Notably, the US president did not publicly respond to the sanctions.
But the prime minister has been forced to hit back at Mr Trump on several occasions, particularly on issues concerning the sovereignty of the Falkland Islands and Northern Ireland.
The US president has previously indicated he might not back the UK’s sovereignty over the Falklands if Argentina launched an attack, after Argentina’s president Javier Milei, an ally of Mr Trump, reiterated his country’s claim to the Falklands in a national televised address.
In response, Mr Burnham said the UK would be “relentless” in defending the Falkland Islanders’ right to be British.
The president again waded into the dispute during a visit to Dublin on Saturday, where he suggested the UK would not “be willing to travel that far” if Argentina invaded the Falklands as it did in 1982.
He also called Mr Burnham “a very nice guy” but on “on the liberal side” on his visit, but opened up a fresh political row over Northern Ireland.
The US president claimed Irish unification was inevitable as he spoke to reporters alongside Taoiseach Micheál Martin, adding it “may as well happen now”.
He said: “I’d love to see it unified. I think it would be a great feather in everybody’s cap if that happened. It’s going to happen eventually.”
In response, Downing Street pointed to comments from Andy Burnham earlier in the week rejecting the prospect of an immediate border poll.
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