"Russia's military activity in the Ukraine continues to be of great concern to us."
Those were the words of U.S. Air Force Secretary Deborah James in a briefing as she talked about the recent deployment of an F-22 to Europe. The F-22 Raptor is the Air Force's most advanced fighter jet, according to CNN.
The deployment is part of the effort "to assure our allies and demonstrate our commitments to security and stability of Europe," James said.
It will be housed in facilities that will be central to U.S. actions if conflict arises in Europe, officials said. Various units have been rotated through Europe in connection with training and exercises in 2015.
Last week, Russian President Vladimir Putin visited the Crimean peninsula without consent of the Ukranian authorities, which by some was seen as a move to spur conflict, CNN reported. Crimea has been under Russian control for about a year.