Tom Vanden Brook, and Gregg Zoroya

USAToday

U.S. troops returning from Ebola-stricken nations will be isolated for 21 days, Defense Secretary Chuck Hagel announced Wednesday, a day after the White House raised concerns about states imposing strict quarantines of health care workers returning from West Africa.

Top commanders for the Navy, Air Force and Marine Corps made the recommendation to Hagel on Tuesday. The Army instituted an isolation requirement for 21 days — the incubation period for the deadly virus — on Monday.

Hagel directed the isolation policy be reviewed in 45 days to see whether it was necessary to continue with it, said Rear Adm. John Kirby, Pentagon press secretary.

"The secretary believes these initial steps are prudent," Kirby said, adding the review period will reveal "what we learn and observe from the initial wave of personnel returning from (West Africa.)"

Hagel's decision goes beyond Pentagon guidelines issued earlier this month that stopped short of requiring isolation, urging only that returning troops be subject to medical monitoring.

During their deployment to West Africa, U.S. troops are not treating Ebola patients but rather are assigned to building clinics and training and testing blood samples for the presence of the virus.

Air Force Col. Edward Thomas, a spokesman for the chairman of the Joint Chiefs of Staff, Army Gen. Martin Dempsey, said civilian doctors returning from West Africa are better able to monitor themselves because of their background, while most of the troops being sent to the area are young and do not have such medical training.

The approach is consistent with military culture, Thomas said. Commanders have implemented stringent requirements for troops returning home in the past, and approach to Ebola is no different, he said.

"At least initially, we think this conservative approach is the right one," Thomas said.

The developments come after the White House urged states on Tuesday to lift mandatory quarantine requirements for volunteer medical workers returning from Ebola-stricken nations out of concern the moves could discourage sorely needed health care workers from volunteering to fight the virus in West Africa. Over the weekend, New York, New Jersey and others implemented the controversial rules.

The federal government's general guidance for health care workers reserves isolation only for those who have been exposed to Ebola directly. Obama and other officials said troops face different situations from civilians in part because they are not in West Africa by choice.

However, President Obama appeared to acknowledge a distinction between a military requirement to isolate troops and his view that mandatory quarantines not be imposed upon civilian medical volunteers returning from West Africa.

"The military is a different situation, obviously. They are not there voluntarily; it's part of their mission that's been assigned to them by their commanders and ultimately by me, the commander in chief," he told reporters Tuesday. "So we don't expect to have similar rules for our military as we do for civilians."

Meanwhile, the Army said Monday that it is implementing a 21-day isolation requirement for all soldiers returning from West Africa. The policy's first impact was on about dozen GIs who arrived over the weekend at a U.S. military installation in Vicenza, Italy, including commander of Army forces in Africa, Maj. Gen. Darryl Williams.

Williams and his troops are being housed in a separate facility and are not allowed contact with family members for the 21-day period. The troops are provided access to a gym, a day room, TV and the Internet. They are being monitored for any signs of infection.