MOSCOW, May 6 -- The Russian Defense Ministry on Tuesday refuted remarks of a senior U.S. military official, saying the activity of long-range warplanes over the Pacific has nothing to do with Ukraine.

Linking Russian warplanes' scheduled flights in the eastern part of the Pacific Ocean to the situation in Ukraine can only attest to the poor knowledge of geography, for these regions are located in different hemispheres, the Interfax news agency quoted a ministry source as saying.

Earlier on Tuesday, Commander of the U.S. Pacific Air Forces Herbert Carlisle said at the Washington Center for Strategic and International Studies that Russian strategic warplanes' activity, including that of TU-95 strategic bombers over the Pacific, has been connected with the events in Ukraine.

The goal of the Russian Air Force's intensified activity in the Pacific region was to demonstrate its capabilities and gather intelligence, Carlisle said.

Russia said the two countries are neighbors through the Bering Strait. "Therefore, seeing Russian warplanes' flights over the neutral waters of the Pacific Ocean as a challenge to the United States is strange," the source said, adding the intensity of U.S. reconnaissance planes' flights in the vicinity of Russian eastern borders has never abated since the end of the Cold War.

Russia-U.S. relations have slid to its low since the end of the Cold War over their opposite approaches to the situation in Ukraine and Russia's accession of Crimea in March.