"There is no impact on the operations," said General John Hyten, the vice chairman of the US Joint Chiefs of Staff.

"The currently assigned missions that we have across the globe are still being executed with the same rules of engagement and the same construct that we've had a month ago or two months ago."

The US military will "continue to adjust as we get different requirements, but there's been no impact on those missions due to the coronavirus," he said.

Hyten said the number of COVID-19 cases among US forces overseas is "very small," so "they have not impacted our ability to conduct operations."

The Pentagon on Wednesday announced a two-month freeze on all planned troop movements around the world, including the deployment and the return home of personnel in theaters of war, in an attempt to curb the spread of the coronavirus.

As of Friday the Pentagon reported 652 cases of COVID-19 among its military and civilian employees, and among Pentagon contractors. One contractor and a military spouse have died from the virus.

There are some 1.3 million military personnel on active duty, as well as 450,000 National Guard volunteers and some 600,000 reservists.