US President Donald Trump said that, amid efforts to continue with legal challenges, he gave Emily Murphy, the head of the General Services Administration, the go-ahead to proceed with a transition to the administration of President-elect Joe Biden.

"I want to thank Emily Murphy at GSA for her steadfast dedication and loyalty to our Country. She has been harassed, threatened, and abused – and I do not want to see this happen to her, her family, or employees of GSA," Trump said in a tweet.

"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."