Milley is working remotely from home following his diagnosis, a Defense Department official told CNN. Butler said in a statement that Milley “can perform all of his duties from the remote location.”
“He has received the COVID-19 vaccines including the booster,” Butler said.
According to the statement, Milley most recently had contact with President Joe Biden on Wednesday, January 12, at Gen. Raymond Odierno’s funeral.
“He tested negative several days prior to and every day following contact with the President until yesterday,” Butler said.
“All other Joint Chiefs of Staff except for one tested negative for COVID-19 yesterday,” he added.
The military has been seeing a sharp uptick in cases among service members in recent weeks, continuing a trend that began during the holiday season.
The DOD reported last week that there were 32,912 Covid-19 cases in service members around the world, marking a dramatic increase from one week earlier, when there were 13,940 cases across the military. Just before Christmas, the number was a far lower, at 5,285 cases.
The Defense Department does not test specifically for the Omicron variant that has been driving the increase in cases around the world, but officials say there is every reason to believe the highly contagious strain is responsible for the soaring case numbers.
This story has been updated with additional information Monday.
CNN’s Devan Cole contributed to this report.