US President Donald Trump was dismissive of Andy Burnham, who is set to become the next UK prime minister, saying he was unfamiliar with him and has only heard that he is “extremely liberal”.

The US president was asked by a reporter on Wednesday about what he knew about Burnham, the former mayor of Greater Manchester who is poised to succeed Keir Starmer in Britain’s latest leadership shake-up.

“I don’t know anything. 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,” Trump said during a White House meeting with Nato Secretary General Mark Rutte.

The president’s comments set the stage for a potentially rocky relationship between the two men.

Burnham has been critical of Trump in the past, describing US politics as “polarised” and “poisonous” while on the campaign trail in June.

As rioters stormed the US Capitol in 2021, he posted on X: “Any UK politician who gave Trump the time of day should be ashamed right now”.