Washington: US First Lady Jill Biden has tested negative for Covid-19 twice and will come out of isolation Sunday, the White House said.

The 71-year-old wife of President Joe Biden tested positive on August 16, nearly two weeks after her husband contracted the virus for a second time.

She is double vaccinated and twice boosted, and experienced mild symptoms. She was prescribed a course of the oral antiviral pill Paxlovid.

"After isolating for five days and receiving negative results from two consecutive COVID-19 tests, the First Lady will depart South Carolina later today for Delaware," her communications director Elizabeth Alexander said in a statement.

Jill Biden had tested positive while on holiday in South Carolina, where she stayed at a private residence.

President Biden, who turns 80 in November, has recently recovered from two separate bouts of the coronavirus.

He first tested positive on July 21 and continued to carry out his duties while isolating at the White House.

After four days of negative tests he again received a positive result on July 30 and entered isolation a second time, before coming out, having recovered fully, on August 7.