Boris Johnson and Joe Biden on Saturday vowed to deepen ties and cooperate on tackling climate change in their first conversation since the US president's inauguration, the British prime minister's office said.
Johnson congratulated Biden on his inauguration and "the two leaders looked forward to deepening the close alliance between our nations", said the statement from Downing Street.
British newspapers reported that Johnson was the first European leader to receive a call from Biden, who earlier spoke to Canadian and Mexican counterparts.
The right-wing Sunday Telegraph reported that Johnson was the first leader outside North America to speak to Biden "after his scheduled call was brought forward two days in what will be seen as a major boost for the special relationship between the UK and US."
Biden on Friday spoke to Canadian Prime Minister Justin Trudeau in his first call to a foreign leader.
The White House in a readout of the call said that Biden "conveyed his intention to strengthen the special relationship between our countries and also "noted the importance of cooperation, including through multilateral organizations, on shared challenges".
Johnson tweeted a picture of himself in shirt-sleeves laughing as he spoke on the phone. "Great to speak to President @JoeBiden this evening," he wrote.
The conversation appeared aimed at warming frosty relations after Biden in 2019 described Johnson as a "physical and emotional clone" of Donald Trump, his predecessor as US president.