Boris Johnson has had his first call with Joe Biden since the new US president entered the White House on Wednesday.
Downing Street said the Prime Minister congratulated Mr Biden on his inauguration, and warmly welcomed his decision to rejoin the Paris Agreement on climate change and the World Health Organisation – both abandoned by Donald Trump.
Following the call, Mr Johnson tweeted: “Great to speak to President Joe Biden this evening.
“I look forward to deepening the long-standing alliance between our two countries as we drive a green and sustainable recovery from Covid19.”
A No 10 spokesman said they had also discussed the potential benefits of a free trade deal, with the Prime Minister reiterating his intention to resolve the outstanding issues as soon as possible.
“The Prime Minister praised President Biden’s early action on tackling climate change and commitment to reach net zero by 2050,” the spokesman said.
“Building on the UK and US’ long history of cooperation in security and defence, the leaders re-committed to the NATO alliance and our shared values in promoting human rights and protecting democracy.
“The leaders looked forward to meeting in person as soon as the circumstances allow, and to working together through the G7, G20 and Cop26 this year.”
It is reported that Mr Johnson is the first European leader to have spoken to the new president, after he had calls on Friday with Canadian prime minister Justin Trudeau and Mexican president Andres Manuel Lopez Obrador.
There will be some relief in Downing Street at the early call amid concerns about the way Mr Johnson’s perceived closeness to Mr Trump would be seen by the new administration.
The Prime Minister is regarded with deep suspicion by some senior Democrats around Mr Biden who – unlike the former president – was no fan of Brexit.
Many were offended by his sideswipe at the “part-Kenyan” Barack Obama during the 2016 EU referendum campaign, while Mr Biden once described him as a “physical and emotional clone” of Mr Trump.
Following the inauguration, No 10 sought to play down Mr Biden’s decision to remove a bust of Winston Churchill from the Oval Office – even though Mr Johnson had criticised Mr Obama when he did the same thing.
The Prime Minister’s official spokesman said: “The Oval Office is the president’s private office and it’s up to the president to decorate it as he wishes.
“We’re in no doubt of the importance that President Biden places on the UK and US relationship and the Prime Minister looks forward to having a close relationship with him.”