US President-elect Joe Biden has solidified his election victory when he won the state of Georgia as President Donald Trump said "time will tell" if another administration takes office soon, the closest he has come to acknowledging that Biden could succeed him.
Edison Research, which made the Georgia call, also projected that North Carolina, the only other battleground state with an outstanding vote count, would go to Trump, finalising the electoral vote tally at 306 for Biden to 232 for Trump.
The numbers gave Biden, a Democrat, a resounding defeat over Trump in the electoral college, equal to the 306 votes Trump, a Republican, won to defeat Hillary Clinton, a 2016 victory that Trump called a "landslide".
At a White House event where he predicted a coronavirus vaccine would be available for the whole population by April, Trump came the closest he has yet to acknowledging that he might leave the White House in January, but said "time will tell".
"This administration will not be going to a lockdown. Hopefully the, uh, whatever happens in the future - who knows which administration it will be? I guess time will tell," Trump said on Friday in his first public remarks in more than a week after losing to Biden.
Trump did not take questions after the event.
Trump, a Republican, has claimed without evidence that he was cheated by widespread election fraud and has refused to concede. State election officials report no serious irregularities, and several of his legal challenges have failed in court.
While Trump had yet to concede, Biden officials reiterated they were moving ahead with transition efforts regardless.
Although the national popular vote does not determine the election outcome, Biden was ahead by more than 5.3 million votes, or 3.4 percentage points. His share of the popular vote, at 50.8 per cent, was slightly higher than Ronald Reagan's share of the vote in 1980 when he defeated Jimmy Carter.
To win a second term, Trump would need to overturn Biden's lead in at least three states but he has failed to produce evidence he could do so in any of them. States must certify their election results before the electoral college meets to select a new president on December 14.
Biden's legal team in Georgia said on Friday they do not expect a hand recount of votes in the state to change the results there.
A Michigan state court rejected on Friday a request by Trump's supporters to block the certification of votes in Detroit, which went heavily in favour of Biden. And lawyers for Trump's campaign dropped a lawsuit in Arizona after the final vote count rendered it moot.
Federal election security officials found no evidence any voting system deleted or lost votes, changed votes "or was in any way compromised", the lead US cybersecurity agency said in a statement.
Biden officials said they would press forward with the transition, identifying legislative priorities, reviewing federal agency policies and preparing to fill thousands of jobs in the new administration.
However, Jen Psaki, a senior adviser to Biden's transition team, stressed on a conference call that Biden still needed "real-time information" from the Trump administration to deal with the resurgent pandemic and national security threats.
Fox News correspondent Geraldo Rivera, a Trump confidant, said he had spoken to the president by phone on Friday and "he told me he would do the right thing".
"He told me he's a realist," Rivera said in an interview with Fox. "He just wants a fair fight."