The F-22 Raptor fighter, the most sophisticated warplane in the U.S. Air Force, is set to move to Europe as a potential deterrent to Russian aggression. The U.S. Air Force refuses to divulge details of when the jets will arrive in Europe, but their deployment comes after Defense Secretary Ash Carter acknowledged that Russia posed "an existential threat" to the United States.

"Vladimir Putin's Russia behaves, in many respects, as - in some respects and in very important respects -as an antagonist. That is new. That is something, therefore, that we need to adjust to and counter. And we're doing that in an approach that I've called strong and balanced," Carter said, according to USA Today.

"Russia's military activity in the Ukraine continues to be of great concern to us and to our European allies. For the air force, an F-22 deployment is certainly on the strong side of the coin," said Air Force Secretary Deborah James at the Pentagon, without giving details about the specific number of planes, date or location of the deployment, reports The Guardian.

"We have allies in Europe that have advanced capabilities. We need and they would like for us to be able to inter-operate in multiple-type scenarios, and so being able to train side-by-side with them and do that training is really important," said Air Force Chief of Staff Gen. Mark Welsh at the news conference with James. Welsh further said that the deployment would allow the F-22 pilots to interact and train jointly with the Eurofighter Typhoons, which have been flying air patrols over the Baltic states, reports Military.com.

With this announcement, the F-22s will be a part of Operation Atlantic Resolve, the effort by the U.S. to reassure NATO allies and partners of America's commitment "in the region in light of the Russian intervention in Ukraine."