The Russian military has announced the deployment of advanced air-defense missiles to the Kurile Islands claimed by Japan.
The S-300V4 air-defense missile systems have entered combat duty on the Kurile Islands, in addition to the shorter-range Tor-M2 missile systems deployed there earlier, Russia's Eastern Military District said in a statement on December 1.
The Russian Defense Ministry's TV station, Zvezda, reported that the air-defense missile systems were deployed on Iturup, one of the four southernmost Kurile Islands.
Russia has continued to build up its forces on the islands, including stationing advanced fighter jets and anti-ship missiles there.
The Soviet Union seized the Kuriles in the final days of World War II from Japan, which continues to assert territorial rights to the islands it calls the Northern Territories. The dispute has kept Russia and Japan from signing a peace treaty formally ending the war.
Decades of diplomatic efforts to negotiate a settlement haven't produced any visible results.
Tokyo is highly sensitive to military moves by Moscow on the strategically important chain of islands that stretch northeast from Japan's Hokkaido to the Russian Far East region of Kamchatka.
Shortly after taking office in September, newly elected Japanese Prime Minister Yoshihide Suga discussed the territorial dispute in a call with Russian President Vladimir Putin.
Former Japanese Prime Minister Shinzo Abe pushed to resolve the dispute during his nearly eight years in power.