"The chairman, the vice chairman and all the service chiefs tested negative," said the official, who requested anonymity.

The Pentagon said a number of senior US military officers were self-quarantining after attending meetings last week with the Coast Guard's vice commandant, Admiral Charles Ray.

"We are aware that Vice Commandant Ray has tested positive for Covid-19 and that he was at the Pentagon last week for meetings with other senior military leaders," said Pentagon spokesman Jonathan Hoffman. "Some meeting attendees included other service chiefs."

"Out of an abundance of caution, all potential close contacts from these meetings are self-quarantining," Hoffman said. "No Pentagon contacts have exhibited symptoms and we have no additional positive tests to report at this time."

The Coast Guard said Ray had tested positive on Monday after experiencing mild symptoms and was quarantining at home.

Hoffman stressed that there has been "no change to the operational readiness or mission capability of the US Armed Forces."

President Donald Trump announced last week that he and First Lady Melania Trump had tested positive for Covid-19.

Trump returned to the White House on Monday after spending several days at Walter Reed National Military Medical Center while the first lady remained at the White House.