The Russian Defense Ministry announced on Thursday it deployed the mobile coastal defense missile system Bastile on the Kuril Islands.
The servicemen will carry a round-the-clock watch on the Matua Island of the Kuril Ridge to monitor the adjacent water area and straits, the ministry said in a statement.
"An autonomous military camp has been organized on the territory of the island by the forces of the (Russian Pacific) fleet's logistics support units where the work has been completed on the improvement of premises intended for year-round service and accommodation of personnel," the ministry said.
Supporting facilities required for maintaining the military equipment and warehouses were built on the island, it added.
"The personnel began to carry out the duty and planned combat training activities," it said.
Commenting on the deployment of the Bastion system, Kremlin spokesman Dmitry Peskov said Russia has the full right to deploy any weapons in any place of its territory.
Asked about the work on a peace treaty with Japan, Peskov said both sides are willing to proceed with it.
"We maintain the political will to continue a comprehensive dialogue with our Japanese partners to find ways to resolve this basic problem," he noted.
Russia and Japan have not resolved the territorial dispute over the islands 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 never signed a peace treaty and technically are still at war. As both sides claim the territories, the question of the Kurils’ sovereignty remains uncertain.
Tokyo regularly protests visits of Russian officials to the islands.
Russian authorities fear the possible deployment of US missile systems on the islands if they are returned to Japan, creating a direct military threat to Russia.