United States President Donald Trump has hinted that he may accept defeat by Joe Biden as media declared the Democrat the winner in Georgia while the counting was still going on, solidifying his lead in the electoral college.

Trump broke his silence after a week without on-camera comments, speaking at a Rose Garden event to herald the imminent authorisation of a COVID-19 vaccine.

During a speech about the vaccine work, Trump insisted that he would never again call for a lockdown to curb the virus' spread. He added: "Hopefully, the, the whatever happens in the future, who knows which administration it will be, I guess time will tell."

Trump, who has so far refused to concede the election to Biden and has vowed to continue to challenge some of the results in courts. This was likely his first time thinking aloud in public of another administration taking over on January 20.

There have been speculations about how he would finally deal with a defeat, with hyperbolic scenarios painted by some of his hard-core critics of him not leaving the White House leading to a constitutional crisis.

An unidentified senior aide to Trump was quoted by NBC as saying that he was likely to accept the election verdict while not admitting that he lost.