The 79-year-old is experiencing mild symptoms and will continue to work, the White House says.
US President Joe Biden has tested positive for Covid-19 and is isolating at the White House.
The 79-year-old, who is fully-vaccinated and has twice received booster jabs, is experiencing “very mild symptoms” and will continue to carry out all his duties, press secretary Karine Jean-Pierre said.
The president is taking the antiviral medicine Paxlovid, her statement added.
He will take part in meetings via telephone and Zoom, the official said.
Consistent with White House protocol the president will continue to work in isolation until he tests negative, Ms Jean-Pierre said,
First Lady Jill Biden is said to have tested negative while in Delaware.
The White House medical unit will inform all close contacts of the president during the day, Ms Jean-Pierre said, including any members of Congress or members of the press who were with Mr Biden during his visit to Massachusetts on Wednesday.
He last tested negative for Covid on Tuesday, the White House said.