The US military has said it is pausing the movement of any new troops into Afghanistan and is quarantining 1,500 troops and civilians who recently arrived in order to protect them from coronavirus.
Troops who are already in the country may have their deployments extended so missions can continue.
The announcement comes as the US is reducing its troops presence in Afghanistan as part of the peace deal signed last month between the Taliban and the United States.
In a tweet, army General Scott Miller, the top commander in Afghanistan, said the military has started new screening procedures for personnel arriving in the country.
21 US and coalition personnel exhibiting flu-like symptoms are in isolation and receiving medical care.
About 1,500 service members, civilians and contractors who have gone to Afghanistan from various countries in the past week are living in screening facilities.
Gen Miller said most are either new deployments or people returning from leave and they are being quarantined “out of an abundance of caution, not because they are sick.”
He added that the US-led coalition is also limiting access to critical personnel and bases.
So far, 21 US and coalition personnel exhibiting flu-like symptoms are in isolation and receiving medical care.