A Russian bomber aircraft approached a U.S. aircraft carrier off the Korean coast on Wednesday and was intercepted by American fighter jets -- the second such incident in less than a month, U.S. defense officials said.

According to the U.S. officials, a Russian bomber came within three to five nautical miles and flew 2,000 feet (610 meters) above the USS Nimitz aircraft carrier and its accompanying ships.

Two U.S. F/A-18 fighters were launched to intercept the Russian aircraft and escort it out of the area, according to one defense official.

Russian bombers over the past year have increased their flights near U.S. territory and U.S. naval assets, demonstrating their long-range strike capability.

In February, two Russian bombers approached the Nimitz near Japan and one flew over the carrier, escorted by a U.S. fighter jet. That was the first Russian overflight of a U.S. carrier since 2004.

Those operations come as Russian officials say they will revive some of the military power and reach allowed to collapse with the Soviet Union.

U.S. defense officials on Wednesday said they did not consider the Russian bomber flight a threat or concern.