Russia’s MiG-31 fighters armed with Kinzhal hypersonic aeroballistic missiles have performed a scheduled flight over the neutral waters of the Sea of Japan, the Russian Defense Ministry said on Tuesday.

"MiG-31 aircraft with Kinzhal hypersonic aeroballistic missiles performed a scheduled flight in the airspace over the neutral waters of the Sea of Japan," the statement read.

The MiG-31 crews practiced in-flight refueling during the mission, the ministry said.

The flights adhered strictly to international airspace rules, it added.