Donald Trump has relented and told officials to start the process of transitioning power to Presidential-elect Joe Biden.
However, the outgoing US President is still challenging the results of the election, describing it as "corrupt".
The decision means Mr Biden - who secured a clear win in both the popular vote and electoral college - is now able to access funding and important briefings ahead of his inauguration in January.
In a series of tweets, Mr Trump said he'd recommended that General Services Administration administrator Emily Murphy 'do what needs to be done with regard to initial protocols, and have told my team to do the same'.
He insisted his team is still moving 'full speed ahead' in challenging the election results.
The US President also reiterated his unsubstantiated claims of voter fraud, saying he "will never concede to fake ballots & 'Dominion' [voting system]".
Mr Trump's decision to begin the transition process comes after a series of bruising legal defeats in his efforts to have the election results overturned.
Recent days have seen several key states such as Georgia and Michigan certify Mr Biden's win in the states, despite efforts by Mr Trump's team to delay the process.
Last week a Pennsylvania judge threw out a case brought forward by the Trump campaign to block the certification of votes in the state, saying their team had come up with no "compelling legal arguments [or] factual proof of rampant corruption".
'A dose of reality'
Larry Donnelly, Law Lecturer at NUI Galway, says Donald Trump was running out of options, and had to begin the formal transition.
He told The Pat Kenny Show that "a dose of reality" has finally hit Mr Trump.
He said: "I think the certification of the results in Michigan, another loss and a court challenge in Pennslyvania, coupled with there being almost no chance of his legal challenges anywhere else succeeding, they've made the president take a long, hard look in the mirror and say that the gig is up.
"I also think if he wants to remain a player, if he wants to run next time, the longer he dallies in the White House and disgraces himself, the more it might inflict political damage on him.
"I don't think he's going to concede outright, I don't think he's going to cooperate excessively, I don't think he's going to do the decent thing.
"But I do think he's going to go."
Mr Donnelly added that he believes the legal challenges will carry on but fears that certain judges would "do the bidding" of Mr Trump were "overwrought".
