Three B-52 Stratofortress bombers and more than 200 airmen are in Spain for a military exercise led by Norway.
The deployment for exercise Cold Response is the latest in a series of steps taken by the Pentagon to reassure allies in Europe who are increasingly worried about Russian aggression.
The bombers are assigned to the 2nd Bomb Wing, Barksdale Air Force Base, Louisiana.
"Strategic bomber deployments enhance the readiness and training vital to rapidly projecting global power and responding to any potential crisis or challenge," Adm. Cecil D. Haney, U.S. Strategic Command commander, said in an Air Force release on Friday.
USSTRATCOM said the bombers would be in the area for a short-term deployment, but did not specify exactly how long they would take part in the mission.
"Supplementing U.S. European Command's forward presence with B-52s exercises the forward operating locations that enable our collective defense capabilities while demonstrating our ability to command, control and conduct global bomber operations," Haney said.
The exercise is meant to rehearse "high-intensity operations in winter conditions," according to the Defense Department. The training of more than a dozen countries is meant to highlight NATO's ability "to defend against any threat in any environment."
Oriana Pawlyk covers deployments, cyber, Guard/Reserve, uniforms, physical training, crime and operations in the Middle East, Europe and Pacific for Air Force Times. She was the Early Bird Brief editor in 2015. Email her at opawlyk@airforcetimes.com.