UK Prime Minister Boris Johnson spoke to Joe Biden on Tuesday during their first official phone call since the US President-elect won the November 3 election against incumbent Donald Trump.

It is believed that Biden chose to telephone Johnson ahead of other leaders in Europe as Downing Street said the two leaders pledged to work closely together.

“In a call this afternoon, the Prime Minister warmly congratulated Joe Biden on his election as President of the United States. The Prime Minister also conveyed his congratulations to Vice President-elect Kamala Harris on her historic achievement,” a Downing Street spokesperson said.

“They discussed the close and long-standing relationship between our countries and committed to building on this partnership in the years ahead, in areas such as trade and security – including through NATO. The Prime Minister and President-elect also looked forward to working closely together on their shared priorities, from tackling climate change, to promoting democracy, and building back better from the coronavirus pandemic,” the spokesperson said.

During the conversation, Johnson is said to have formally invited Biden to attend the COP26 climate change summit that the UK is hosting in Glasgow next year.

“They also looked forward to seeing each other in person, including when the UK hosts the G7 Summit in 2021,” the spokesperson added.

Biden was declared the winner on Saturday as he edged passed the 270 electoral college votes mark. However, counting is ongoing on in some states, with President Donald Trump disputing the result.

Soon after his phone call, Johnson also issued a Twitter statement to say that he is looking 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.