Russia will reinforce its troops and military facilities in the Kuril Islands, which are at the center of a heated territorial dispute between Russia and Japan.

Japan’s public broadcaster NHK reported that Russian Defense Minister Anatoly Serdyukov announced a plan to spend seven billion rubles over the next two years on beefing up Russia’s military facilities in the Kurils. He made the announcement during a visit to the far eastern Kamchatka Peninsula on Monday.

The Russian military plans to deploy three-thousand-500 troops to the islands while building new bases and introducing antiaircraft missiles and a communication system to two of the four islands.

Japan has been demanding the return of the Kurils, claiming that the four islands, northwest of Hokkaido, are historically Japanese territory. But Russia has flatly rejected the demand, saying that the islands have been under Russian rule since the end of World War Two.