WASHINGTON, July 30. /TASS/. US President Joe Biden tested positive for Covid Saturday, and returns back to quarantine, Biden’s doctor Kevin O’Connor said in a written statement, adding that the US leader feels well and experiences no symptoms.

"After testing negative on Tuesday evening, Wednesday morning, Thursday morning and Friday morning, the President tested positive late Saturday morning, by antigen testing," the doctor said, adding that Biden "has experienced no reemergence of symptoms and continues to feel quite well."

However, due to the positive antigen test, "Biden will reinitiate strict isolation procedures."

O’Connor noted that the President was taking Paxlovid medicine, known for return of symptoms in some patients after negative test results, or, as in Biden’s case, positive tests results. According to the doctor, there "is no reason to reinitiate treatment at this time," but the specialists will continue observing the President’s condition.