Washington: US President Joe Biden has had two negative Covid-19 tests and no longer needs to isolate after recovering from infection, his White House doctor said Wednesday.

"Yesterday evening and then again this morning, he tested NEGATIVE for the SARS-CoV-2 virus by antigen testing," presidential physician Kevin O'Connor wrote in a memorandum, adding that Biden had already completed a course of the Paxlovid therapeutic.

"Given these reassuring factors, the President will discontinue his strict isolation."

The US leader had been isolated in his White House residence since testing positive for the coronavirus last Thursday.

He has been carrying out his full duties, but observed a lighter schedule during his recovery.

While now out of isolation, the president will wear a mask for 10 days when around others and continue to test regularly for the virus in case of a "rebound," O'Connor said.

Biden has no fever, the doctor added, noting "his symptoms have been steadily improving, and are almost completely resolved."

Biden, 79, is the oldest person ever in the US presidency but his physician says he is generally in good health. He has been fully vaccinated and received two booster shots against the coronavirus.