WASHINGTON (Reuters) -- The head of U.S. air forces in the Pacific said Monday that Russia's intervention in Ukraine had been accompanied by a significant increase in Russian air activity in the Asia-Pacific region in a show of strength and to gather intelligence.
Carlisle said the number of long-range Russian patrols around the Japanese islands and Korea had increased "drastically." He said there had also been "a lot more ship activity as well."
Speaking at Washington's Center for Strategic and International Studies think tank, Carlisle showed a slide of a U.S. F-15 fighter jet intercepting a Russian "Bear" aircraft over Guam. He used the Cold War NATO name for Russia's Tupolov Tu-95 strategic bomber.
"That's to demonstrate their capability to do it, it's to gather intel," Carlisle said, adding that the surveillance had included observation of military exercises involving U.S. forces in South Korea and Japan.
"There are things that are concerning with respect to how they operate and how transparent they are with other nations in the vicinity," he said.
Carlisle did not give details of the incidents, and the Defense Department and the U.S. Air Force and Navy in the Pacific did not immediately respond to a request for more information.
Russian President Vladimir Putin announced in 2007 that Russia was resuming Soviet-era sorties by its strategic bomber aircraft near NATO airspace that were suspended in 1992 after the collapse of the Soviet Union.
Putin, who made the announcement during a joint military exercise with China, said the move was necessary to guarantee Russia's safety and that other nations had not followed Moscow's example in suspending such flights.
(Reporting by David Brunnstrom; Editing by Ken Wills)