KYODO, March 26 (Kyodo) - The Russian military has started a military exercise involving more than 3,000 troops on a chain of islands — including those disputed with Japan — Russian news agency Interfax reported.

It is the first drill on the disputed islands off Japan’s northernmost main island of Hokkaido since Russia’s Foreign Ministry announced earlier this week it will suspend territorial talks with Japan. Russia is withdrawing from the talks over Tokyo’s sanctions against Moscow in the wake of the invasion of Ukraine.

Some hundreds of military vehicles are participating in the drill under a scenario of launching a counterattack against enemy forces attempting to land, the report said Friday.

Russia is seen as building up its forces on the islands, called the Northern Territories by Japan and the Southern Kurils by Russia. The territorial dispute has prevented the two countries from concluding a postwar peace treaty.

Japan claims the Soviet Union illegally seized the four islands — Kunashiri, Etorofu, Shikotan and the Habomai group of islets — soon after Japan’s surrender in World War II in August 1945, while Moscow argues the move was legitimate.

Last week, the Defense Ministry said that it had spotted four large Russian amphibious warfare ships sailing through a strait in northeastern Japan as they traveled west, possibly toward Europe to aid in the war in Ukraine.

Days before that, Japan protested after six Russian Navy vessels passed through the Soya Strait between Cape Soya in Hokkaido and the Russian island of Sakhalin.

The Japanese government conveyed to Moscow that it is closely monitoring the Russian military’s growing activities in areas around Japan amid the Ukraine crisis, while expressing grave concern over the moves.

That incident came after 10 Russian warships passed through the Tsugaru Strait between Hokkaido and Japan’s Honshu main island last week. On Friday, Matsuno said Japan had also lodged a protest with Moscow after the Russian Defense Ministry said it had conducted a missile drill on the Moscow-held, Tokyo-claimed islands off Hokkaido on March 11.