Boris Johnson has welcomed a "refreshing" conversation with Joe Biden as the Prime Minister labelled Donald Trump the "previous president" while the Republican continues to contest the election.
President-elect Mr Biden issued Mr Johnson with a warning that Brexit must not jeopardise the Northern Ireland peace process during their first call since the November 3 vote.
But the Prime Minister on Wednesday focused on their shared values of standing up for Nato and tackling the climate crisis, two areas Mr Trump rode roughshod over.
Mr Johnson told PMQs he continues to have a strong relationship with Mr Trump, who has refused to commit to a peaceful transition of power while making baseless allegations of voter fraud.
I just spoke to @JoeBiden to congratulate him on his election. I look forward to strengthening the partnership between our countries and to working with him on our shared priorities – from tackling climate change, to promoting democracy and building back better from the pandemic.
— Boris Johnson (@BorisJohnson) November 10, 2020
The Prime Minister said he had an "excellent conversation" with Mr Biden on Tuesday afternoon when they strongly agreed on the need to "once again... stick up for Nato and to work together in the fight against climate change".
"It was refreshing, I may say, to have that conversation and I look forward to many more," Mr Johnson told MPs.
Labour's Angela Eagle pressed for his advice to his "erstwhile best friend" Mr Trump as he continues to refuse to accept the result of the election, which she said is "both embarrassing for him and dangerous for American democracy".
Mr Johnson replied: "I had and have a good relationship with the previous president, I do not resile from that – it is in the duty of all British prime ministers to have a good relationship with the White House."
The Prime Minister was among the first world leaders to secure a call with Mr Biden since his victory over Mr Trump.
Mr Biden's transition team said he expressed his desire to "strengthen the special relationship" and "reaffirmed his support for the Good Friday Agreement", in a warning over Brexit.
He has in the past warned that a trade deal with the US is "contingent" on there being no return to a hard border on the island of Ireland amid unease over the Prime Minister's Brexit legislation.
The Democrat has also said that the peace process must not "become a casualty of Brexit" in a warning over the controversial UK Internal Market Bill.
The Prime Minister's official spokesman said: "They had a very positive call. What they talked about was the importance of implementing Brexit in such a way that upholds the Good Friday Agreement and the Prime Minister assured the president-elect that that would be the case."
The spokesman added that "we have been steadfast in our support for Nato and in meeting our commitments in terms of the GDP spending on defence and security, so the PM obviously had an opportunity to reiterate that to the president-elect".
He said: "There are a number of issues where we look forward to working with the president-elect, on foreign policy priorities such as China, Iran and Russia.
"We're also committed to working together to promote human rights around the world as well."
A swift call with the incoming president is highly coveted but it will be particularly welcomed by Mr Johnson amid concerns the pair could face diplomatic difficulties.
They have never met before and Mr Biden has likened the Prime Minister to a "physical and emotional clone" of Mr Trump.
In other controversies, allies of Mr Biden, who was Barack Obama's vice-president, have not forgiven Mr Johnson for highlighting the first African American president's "part-Kenyan" heritage, claiming it had given him an "ancestral dislike of the British empire".
Later on Tuesday, Mr Biden, who speaks proudly of his Irish heritage, spoke to Ireland's Taoiseach Micheal Martin where he again stressed his commitment to the Good Friday Agreement.
... for example, the Paris Accord and the WHO. I congratulated him on the historic nature of his election and that of @KamalaHarris and we agreed to work closely together. I also invited him and @DrBiden to come back to Ireland when we will properly mark their success 🇮🇪🇺🇸
— Micheál Martin (@MichealMartinTD) November 10, 2020
Mr Biden had a series of calls with European leaders on Tuesday, also speaking to German chancellor Angela Merkel and French president Emmanuel Macron. The order of the calls was not clear.
Canadian prime minister Justin Trudeau said he spoke to Mr Biden on Monday, in what was reported to be his first call with a world leader since his election.
Asked if Sir Keir Starmer would condemn Mr Trump's actions since the election, a spokesman for the Labour leader said: "Donald Trump's actions are wrong – and the British Government should say so.
"Any attempts to undermine democratic process should not be left unchallenged.
"We call out that in other countries across the world, and we should be able to do so with our friends and allies in America.
"His actions are wrong and the British Government shouldn't be afraid to say so.
"I think the actions are deeply concerning and they undermine, not only the democratic process in America, but the democratic process across the world.
"They should not be left unchallenged, and the British Government should call them out."