The Russian Defense Ministry's newspaper says the military fired new surface-to-ship missiles in a drill last autumn on one of the four Russian-controlled islands that Japan claims.
Krasnaya Zvezda reported on Wednesday that a missile unit belonging to the Russian Pacific Fleet conducted the exercise on Etorofu Island with the Bal system.
The system has a range of about 130 kilometers and is used for coastal defense. It has been installed in the islands, which Japan calls the Northern Territories, from 2016.
The report says the unit has been commended by the military two years in a row for its high skill and stresses that units tasked with coastal defense of the islands have been enhancing their capability.
The Japanese government maintains the islands are an inherent part of Japan's territory. It says the islands were illegally occupied after World War Two.
Tokyo has lodged protests with Moscow every time the Russian military conducted drills on and around the four islands. But Russia has dismissed the protests.