Russia on Monday said it conducted air defense exercises on the Kuril Islands in its Sakhalin Oblast region.
"During the training, missile launches against air targets were performed. According to the results of the training, the S-300V4 air defense systems successfully 'destroyed' 100 percent of the targets upon entering the affected area," the Eastern Military District said, as quoted by Russian news agency Interfax.
Russia has a territorial dispute over the Kuril Islands with Japan, which it has not signed a peace treaty with since World War II.
At the 1945 Yalta Conference, the Soviet Union agreed to start military operations on the eastern front under an agreement with its western allies, and in exchange, received some Japanese territories, including the Kuril Islands.
After the war, however, Japan rejected the Soviet Union's sovereignty over the islands.
Due to the dispute, Russia and Japan have never signed a peace treaty and are technically still at war. As both sides claim the territories, the question of Kurils’ sovereignty remains uncertain.