The US President made the admission in a tweet along with more unfounded claims the vote was unfairly and deliberately stacked against him.
Donald Trump wrote of his soon-to-be successor: “He won because the election was rigged.
“NO VOTE WATCHERS OR OBSERVERS allowed, vote tabulated by a radical left privately owned company, Dominion, with a bad reputation & bum equipment that couldn’t even qualify for Texas (which I won by a lot!), the Fake & Silent Media, & more!”
It is a significant acknowledgement from Mr Trump, who despite losing both the Electoral College and popular vote has refused to follow tradition and accept the result.
Donald Trump lost the 2020 US presidential election and Joe Biden surpassed the 270 electoral college votes required to be named president-elect.
Yet, at the time of writing, Trump is yet to formally concede the election or congratulate Biden on his victory and is now pursuing baseless claims of electoral fraud against the Democrats and attempting to file legal cases.
Last week Mr Trump became the first president since 1992 to fail to get re-elected, following projections Mr Biden had successfully swung the key states of Pennsylvania, Arizona and Georgia to win the White House.
Since then, the Republican incumbent has launched legal challenges and tried to undermine the validity of the result – but failed to produce any significant evidence of the mass ballot stuffing and voter fraud he is alleging.
World leaders and former presidents – including George HW Bush – have all treated the contest as finished, and sent their messages of congratulations to Mr Biden.
Prime Minister Boris Johnson is among those to already be treating the former vice-president as the winner and a change of administration in January as inevitable.