President Joe Biden called Donald Trump to congratulate him on his victory Wednesday and invited his Republican successor to hold a meeting in the "near future," the White House said.

In his call with Trump, "President Biden expressed his commitment to ensuring a smooth transition and emphasised the importance of working to bring the country together," a White House statement said.

Biden also spoke with Kamala Harris and "congratulated the Vice President on her historic campaign," the statement said, adding that the president on Thursday "will address the nation to discuss the election results and the transition". 

Harris meanwhile also called Trump on Wednesday to congratulate him for winning the 2024 presidential election, one of her senior aides said.

Democrat Harris discussed with Trump the importance of a peaceful transfer of power and being a president for all Americans, said the aide speaking on background, confirming that Harris will deliver remarks in Washington later Wednesday.

Trump's team said the president-elect had agreed with his White House rival on the need to unify the nation after their contentious campaign.

"President Trump acknowledged Vice President Harris on her strength, professionalism, and tenacity throughout the campaign, and both leaders agreed on the importance of unifying the country," said spokesman Steven Cheung.