U.S. defense secretary tests positive for coronavirus.

Defense Secretary Lloyd J. Austin III has tested positive for the coronavirus, he announced on Sunday evening.

In a statement posted to his Twitter account, Mr. Austin said he had tested positive for the virus on Sunday morning, after experiencing symptoms while at home on leave.

“My symptoms are mild, and I am following my physician’s directions,” Mr. Austin said, adding that he planned to quarantine at home for the next five days while virtually attending key meetings and discussions “to the degree possible.”

“I will retain all authorities,” he said, adding that Kathleen Hicks, the deputy secretary of defense, would represent him as appropriate in other matters.

In sharing his diagnosis, the secretary of defense stressed that his fully vaccinated status — including a booster received in early October — was to thank for his mild symptoms.

“I am grateful,” Mr. Austin said, adding that vaccines remained a requirement for the military. He added: “The vaccines work.”

President Biden and other White House staff had been informed of Mr. Austin’s diagnosis, and contact tracing was being conducted, he added, noting that his last meeting with the president had been more than a week prior, and that he had received a negative test result for the virus that morning.

“I have not been in the Pentagon since Thursday, where I met briefly & only with a few staff,” Mr. Austin said. “We were properly masked & socially distanced throughout.”