Russia's state-run news agency has shown footage of what it calls a missile drill conducted by the country's Pacific naval fleet in the Sea of Japan.

The fleet has been conducting a large-scale exercise in the Far East since last Friday. The fleet's command center is in the eastern port city of Vladivostok.

The news agency on Tuesday released the footage, saying the purpose of the missile drill was to ward off enemy submarines.

Details of the drill were not revealed, but the footage shows projectiles being fired from a warship several times.

The Russian Defense Ministry says as part of the exercise, it deployed a nuclear-powered submarine from its base in the Kamchatka Peninsula to the Pacific Ocean.

The ministry also revealed plans to conduct a drill aimed at preventing enemies from landing on the islands known in Japan as the Northern Territories.

Russia controls the islands. Japan claims them. The Japanese government maintains the islands are inherent part of Japan's territory. It says the islands were illegally occupied after World War Two.

Russia issued navigation warnings from Tuesday through Saturday, saying that it will conduct missile drills in waters around Etorofu Island, one of four islands claimed by Japan.

The Japanese government has expressed concerns about the Russian military's increasing activity around Japan.

It has lodged a protest through diplomatic channels, saying that Russia's military buildup in the Northern Territories is unacceptable as it goes against Japan's stance on the islands.

These moves come amid heightened tensions between Russia and western nations, as well as Japan, over the situation in Ukraine.