Boris Johnson has praised US President Joe Biden as a "big breath of fresh air" after the Donald Trump era.
The Prime Minister downplayed Brexit tensions over Northern Ireland after talks with Mr Biden, insisting that there was "absolutely common ground" over protecting hard-won peace in the region.
The row over Northern Ireland's trading arrangements threatened to overshadow Mr Johnson's first meeting with the US President at the G7 summit in Cornwall, which kicks off on Friday.
But the pair were pictured laughing together as they took in the views in Carbis Bay on Thursday with their wives, First Lady Jill Biden and Carrie Johnson.
Speaking after the talks, Mr Johnson said: "It's wonderful to listen to the Biden administration and Joe Biden because there's so much that they want to do together with us – on security, on Nato, to climate change.
Boris Johnson and his wife Carrie Johnson walk with US President Joe Biden and US First Lady Jill Biden
(Image: POOL/AFP via Getty Images)
"It's fantastic, it's a breath of fresh air."
Mr Johnson said the leaders were in "complete harmony" over the impact of Brexit on the Good Friday Agreement, which enshrines peace in Northern Ireland.
Mr Biden, who is proud of his Irish roots, reportedly took the rare step of ordering the most senior US diplomat in London, Yael Lempert, to deliver a formal protest on Northern Ireland with Brexit minister Lord Frost on June 3.
Asked if the President had challenged him on the issue, Mr Johnson said: "No, he didn't.
"But what I can say is that America – the United States, Washington – the UK plus the European Union have one thing we absolutely all want to do and that is to uphold the Belfast Good Friday Agreement and make sure we keep the balance of the peace process going.
"That's absolutely common ground and I'm optimistic that we can do that."
President Biden said he had a "very productive meeting" with the PM – and underlined the special relationship between both nations.
He told reporters in Cornwall: "We affirmed the special relationship – that is not said lightly – the special relationship between our people and renewed our commitment to defending the enduring democratic values that both our nations share."
Mr Johnson reportedly dislikes the term as he thinks it makes the UK sound needy.
President Biden also announced the US was buying 500 million Pfizer doses for countries in “dire need in the fight against this pandemic”.
Hailing the “historic” move, he said: “We are taking a major step that will supercharge the global fight against this pandemic.
“We are doing this to save lives, to end this pandemic, period.”
The doses will start to be shipped in August, with 200 million sent in 2021 and 300 million in the first half of next year.
A Downing Street spokesman said the leaders agreed to work to reopen travel between the US and the UK and to work together to defeat the spread of coronavirus around the world.
On the vexed issue of Northern Ireland's post-Brexit trading arrangements, the spokesman said: "The Prime Minister and President both reaffirmed their commitment to the Belfast (Good Friday) Agreement and to protecting the gains of the peace process.
"The leaders agreed that both the EU and the UK had a responsibility to work together and to find pragmatic solutions to allow unencumbered trade between Northern Ireland, Great Britain and the Republic of Ireland.
"The Prime Minister outlined his ambitions to further expand opportunities for all the people in Northern Ireland and hoped that the US would continue to work with the UK to boost prosperity there."