Army Pvt. Ethan Phelan Melzer submitted his plea in a U.S. District Court, Southern District of New York.
A video has emerged of a Navy ship playing the Italian national anthem for the European country hard hit by the coronavirus.
Current policy, they say, conflicts with local safety guidelines.
"The Army's order is in effect immediately through May 6, 2020, or until further notice," USFK said
This is the second confined case out of 75,000 U.S. service members serving in countries where the virus has rapidly spread.
The UN peacekeeping missions have about 100,000 people in peacekeeping operations in 15 countries.
The number of confirmed cases jumped in Italy to 1,694, the country's Civil Protection Agency reported.
Italian prosecutors are investigating several U.S. paratroopers after one of them was accused of punching a local man.
Americans assigned to Air Force bases in Europe could soon be paying higher rents for off-base homes.
A historian tracked down the untold story of 15 U.S. soldiers of Italian origin who were murdered by Nazis in Italy.