Chairman of the Joint Chiefs of Staff, US Army General Mark A. Milley, responds to questions during a House Armed Services Committee hearing in the Rayburn House Office Building in Washington, US, September 29, 2021. (Reuters photo)

Chairman of the US Joint Chiefs of Staff General Mark Milley, who is fully vaccinated, has been tested positive for COVID-19 and is isolating, according to a US military spokesman.

Colonel Dave Butler, the spokesperson for the Joint Staff, said on Monday that Milley’s most recent contact with US President Joe Biden was on January 12 at the funeral of retired General Raymond Odierno, who died at the age of 67.

Butler said that Milley is experiencing very minor symptoms and can perform his duties remotely.

The spokesman said Milley is fully vaccinated against the COVID-19 and has also received a booster vaccine dose.

Meanwhile, the Marine Corps announced that its Commandant General David Berger tested positive for coronavirus.

The performance of his duties will remain unaffected, commandant spokesperson Maj. Eric Flanagan said in a statement to The Hill.

Milley and Flanagan are the latest top US military officials to test positive for COVID-19 this month.

Earlier this month, Pentagon chief Lloyd Austin announced he had tested positive.

As my doctor made clear to me, my fully vaccinated status - and the booster I received in early October - have rendered the infection much more mild than it would otherwise have been, Austin said.

He tested negative on Jan. 9 and exited isolation to return to work at the Pentagon.

This comes after the Defense Department last month tightened restrictions at its headquarters over concern about the highly transmissible Omicron variant.

The military is confronted with the challenge of maintaining military preparedness for troops, often in close quarters on ships and planes.