The Russian Air Force says its long-range planes always comply with international law during flights over the Pacific Ocean. It comes after a U.S. defence official anonymously claimed that a Russian Tupolev-95 plane flew just 600 metres above the American

U.S. fighters are said to have escorted the Russian bombers out of the area where the Nimitz was operating.

The U.S. allegations follow earlier claims by Japan that a Russian Tupolev-95 bomber entered Japanese airspace on Saturday and was there for three minutes.

Russian Air Force command rejects the claims, saying its long-haul missions were performed in full accordance with international law.

“Russia renewed flights of long-range aircraft in August 2007 in the Pacific, Atlantic and Arctic Oceans, as well as the Black Sea. All the flights are carried out in strict accordance with international rules. We do not trespass on borders of other states. We file all the necessary applications in advance and notify the parties concerned,” Aleksandr Drobyshevskiy, Russian Air Force spokesperson said.

“On February 9, four TU-95 planes successfully completed their ten-hour flight over the Pacific Ocean. We've reported that on Saturday. The strategic aircraft performed the special tasks. Two Russian planes were followed by Japan's F-15 planes and F-18 planes from U.S. aircraft carrier Nimitz which was in the area patrolled by the Russian planes,” he said.

Political analyst Aleksandr Pikaev from the Carnegie Moscow Center says such flights are performed by many countries.

“You need to train pilots – so that you need to let bombers fly,” he said.