US President Joe Biden will make a painful address to the nation Thursday, vowing a peaceful transfer of power to Donald Trump after his political nemesis scored a crushing election win over Kamala Harris.

In what promises to be an agonizing moment for Biden, he will speak in the Rose Garden of the White House at 11am (1600 GMT) to "discuss the election results and the transition" to Trump's second term.

The 81-year-old dropped out of the race against Trump in July and handed the Democratic nomination to vice president Harris -— but is now likely to see his legacy dismantled by the Republican's stunning comeback.

Biden is however apparently determined to draw a stark contrast with Trump, whose refusal to accept his own 2020 election defeat by Biden culminated in the violent January 6, 2021 assault by Trump supporters on the US Capitol.

Falsely claiming voter fraud, Trump also refused to attend Biden's inauguration and did not allow a proper transition.

The White House said Biden spoke with Trump on Wednesday and "expressed his commitment to ensuring a smooth transition and emphasized the importance of working to bring the country together."

Biden is meanwhile striking a presidential tone by calling Trump and inviting him to meet at the White House, despite their long history of bitter animosity.

Trump campaign spokesman Steven Cheung said Trump "looks forward to the meeting, which will take place shortly, and very much appreciated the call."

It would be the first time they had met since Biden's disastrous debate performance against Trump in June that forced him out of the race.

- Trump 2.0 -

The United States and the world face a radically transformed political landscape after Trump's overwhelming victory.

US voters backed Trump's hardline right-wing policies and rejected Biden and Harris's record, especially on the economy and inflation, exit polls showed.

World leaders swiftly pledged to work with Trump, despite concerns in much of the globe about his nationalist "America First" approach and pledges to slap huge tariffs on foreign imports.

Trump's choices for his own White House team will be in the spotlight, with the world's richest man Elon Musk and vaccine skeptic Robert F. Kennedy Jr. both in line for roles.

The Trump campaign's transition team said Wednesday that "in the days and weeks ahead" Trump would be seeking the "best people."

Armed with a sweeping mandate, Trump 2.0 promises to be more untrammeled than his first chaotic presidency -- and could dismantle huge chunks of Biden's legacy.

Trump could start by halting the incumbent's billions of dollars in military aid for Ukraine's fight against Russia's 2022 invasion.

He has repeatedly suggested he would end the war by pressuring Kyiv to make territorial concessions to Russian President Vladimir Putin, a man Trump has repeatedly praised.

Ukraine's President Volodymyr Zelensky spoke with Trump on Wednesday to congratulate him and urge a "just peace."

Trump will also return to the White House as a climate change denier, poised to take apart Biden's green policies with his pledge to "drill, baby, drill" for oil.

Ultimately Biden's legacy was supposed to be a Harris victory that would keep Trump out of power -- but many Democrats feel he waited too long to step aside for his vice president.

He paid tribute to Harris after her concession speech on Wednesday, saying that "what America saw today was the Kamala Harris I know and deeply admire."

One thing Biden and Trump do have in common however is age.

Already 78, Trump is on course to break Biden's record as the oldest-ever sitting president during his four-year term. He will surpass Biden, who is set to step down in January at the age of 82.