五角大楼 press secretary John Kirby made the announcement during a news conference Thursday in Washington.
Some units from Davis-Monthan are among the 8,500 troops placed on heightened preparedness for deployment should 俄国 invade Ukraine.
Other military installations with units put on heightened preparedness include Fort Bragg in North Carolina, Fort Campbell in Kentucky, Fort Carson in Colorado, Fort Hood in Texas, Fort Polk in Louisiana, Robins Air Force Base, Fort Stewart in Georgia and Wright-Patterson Air Force Base in Ohio.
Kirby said the units include medical support, aviation support, logistics support and combat formations.
Department of Defense officials said they are monitoring the buildup of forces in the western part of Russia and in Belarus.