Dec 6 (Reuters) - Russia's defence ministry has said it has deployed mobile coastal defence missile systems on a northern Kuril island, part of a strategically located chain of islands that stretch between Japan and the Russian Kamchatka Peninsula.The Russian Bastion systems, which have missiles with a flight range of up to 500 km (310 miles), were deployed on the island of Paramushir, the Russian defence ministry said on Monday.Japan's Chief Cabinet Secretary Hirokazu Matsuno told a Tuesday news conference that the government will closely monitor the Russian military activity, adding it has been intensifying in the far east regions in tandem with Moscow's invasion of Ukraine.The Washington-based think tank Center for Strategic and International Studies said in a September report that overshadowed by the invasion of Ukraine, Moscow's militarisation of the Kuril Islands "has flown largely under the radar."Russia withdrew from peace treaty talks with Japan and froze joint economic projects related to the disputed Kuril Islands because of Japanese sanctions over Russia's invasion of Ukraine."