Russia holds naval drills in Sea of Japan

Russian troops taking part in the country's largest-ever war games on Saturday held drills in the Sea of Japan, despite Tokyo's concerns about a Russian military buildup in the area.

The exercises were part of the Vostok-18, or East-18, war games that kicked off in eastern Russia on September 11 and will run until Monday.

Defence Minister Sergei Shoigu has described the week-long operation, which involves nearly 300,000 soldiers, 36,000 vehicles, 1,000 planes and 80 warships, as Russia's biggest-ever war games.

They are also taking place in eastern Siberia and the far-eastern Pacific region, with Chinese troops involved.

On Saturday, the armed forces simulated marines capturing a shoreline area at the Klerk military training ground on a peninsula in the far eastern Primorye region supported by aviation and artillery.

"What's special about this exercise is that it involves the marines, aviation, warships from the Pacific Fleet, artillery, sappers and other specialists," Major-General Dmitry Kovalenko told journalists.

Japan has raised concerns over Russia's military buildup in the region, particularly on the Kuril Island chain, four of which are claimed by Tokyo in a dispute dating back to World War II that has prevented the two nations from ever signing a peace treaty.

Speaking Thursday as he watched the drill, President Vladimir Putin promised to "further reinforce" the armed forces and supply them with "the latest generation weapons and technical equipment" at a time of rising tension in Moscow's ties with Washington and Brussels.

While Russia insists the war games are long-planned and purely defensive in nature, NATO has said that they are simulating "large-scale conflict.