Andy Burnham’s initial conversation with Donald Trump was described as "extremely warm" by Downing Street, following the US leader’s positive appraisal of their phone call.
The Makerfield MP secured an early endorsement from Mr Trump, with the discussion taking place within an hour of Mr Burnham’s arrival at Downing Street.
In other diplomatic developments, newly appointed Foreign Secretary Ed Miliband is expected to hold his first bilateral talks with his US counterpart, Marco Rubio.
Their meeting is anticipated during Mr Miliband’s trip to the Philippines for the ASEAN summit on Wednesday.
However, Downing Street would not be drawn on any potential future plans for North Sea drilling, despite Mr Trump having championed a policy change under Mr Burnham’s leadership.
The conversation between Mr Burnham and the US leader reportedly lasted around 20 minutes.
The Prime Minister’s spokesperson told reporters: “It was an extremely warm call and I think that’s reflected in both sides’ readouts.”
After the call, Mr Trump said the new prime minister “has got a big job ahead of him, but he will be able to do it” and pledged that the US “will be there to help”.
It will assuage fears after the Republican president previously described Mr Burnham as “extremely liberal” and “mayor of a town”.
The British embassy in Washington hailed the importance of the call as “underscoring the importance of the UK-US partnership from day one”.
It signals a fresh start in the transatlantic partnership after relations with Sir Keir Starmer grew increasingly fractious over the Iran war.
Mr Burnham will continue letting the US use UK bases for defensive strikes against Iran as attacks from both sides ramp up again.
He agrees with the decision taken by Sir Keir on Friday, before he handed over to Mr Burnham, to carry on with the existing policy, Bloomberg has reported.
Mr Burnham was buoyed in Mr Trump’s eyes after reports he could back new oil and gas drilling in the North Sea, which the president has championed.
Mr Trump said at the weekend said people in Aberdeen would be “dancing in the streets” at such a move, albeit unconfirmed.
The president, a vocal supporter of fossil fuels, insisted further drilling in the North Sea would “make the United Kingdom, from a Poverty Stricken Disaster, to one of the Richest Countries anywhere in the World”.
In his Truth Social post, Mr Trump said the two discussed North Sea oil, trade, and demining of the Strait of Hormuz.
On Tuesday, Downing Street sidestepped questions about whether Mr Trump had the right impression about Mr Burnham’s plans for North Sea oil.
The Prime Minister’s official spokesman pointed back to previous words from Mr Burnham about “the need to make the economy work for everyone. In terms of North Sea and the plans around that, we’ll obviously update when we have an update”.
Mr Miliband, whose held the energy and net zero brief under Sir Keir, has been a strong supporter of Labour’s manifesto commitment on the North Sea.
Labour’s 2024 manifesto said the party would not issue new North Sea licences.
The newly appointed Energy Secretary, Miatta Fahnbulleh, said the manifesto was clear there is scope to exploit existing licences and that oil and gas are “part of the mix” going forward – but would not be drawn on whether there are plans to go further.
“We’re trying to take the country through a transition coming up to 2050. We recognise the role and the important role that oil and gas will play.”
She said Mr Miliband would “charm” his US counterparts when asked about reports that the Trump administration is unhappy that Mr Miliband has been appointed Foreign Secretary.
“He’s super strategic. He’s super smart. He builds great relationships, so no doubt he’s going to charm everyone in the US,” she added.
