US President Donald Trump says he has instructed his team to "do what needs to be done" on initial protocols for transitioning to a Joe Biden presidency.
CNN reported it had seen a letter from administrator Emily Murphy that informed President-elect Joe Biden that the Trump administration was ready to begin the formal transition process.
The letter has been the White House's biggest step towards conceding the presidential election win.
Murphy said she had not been pressured by the White House to delay the formal transition and did not make a decision "out of fear or favouritism," saying she "did not receive any direction to delay my determination".
Then, in a tweet, Trump said he wanted to thank Murphy for her steadfast dedication and loyalty to the country, and he was recommending that she and her team "do what needs to be done with regard to initial protocols".
"She has been harassed, threatened, and abused - and I do not want to see this happen to her, her family, or employees of GSA. Our case STRONGLY continues, we will keep up the good ... fight, and I believe we will prevail! Nevertheless, in the best interest of our Country, I am recommending that Emily and her team do what needs to be done with regard to initial protocols, and have told my team to do the same," he wrote.
A Trump appointee, Murphy had previously refused to move forward with the process, locking the President-elect's team out of speaking with federal agencies.
Joe Biden's victory in the swing state of Michigan has now been certified, further narrowing the legal routes Trump can take to change the election result.