Japan's Defense Ministry says five Russian Navy vessels were spotted in the Pacific Ocean off the northern prefecture of Hokkaido on Thursday. It says the ships' activities are likely part of a massive naval exercise by Russia.
The ministry said on Friday that a Maritime Self-Defense Force vessel confirmed that the Russian ships, including a destroyer and a frigate, were about 170 kilometers southeast of the Nemuro Peninsula in eastern Hokkaido.
Earlier, Russia's Defense Ministry said a massive drill in the Pacific, involving over 40 vessels and about 20 aircraft, was scheduled for last Friday or later.
In relation to the drill, Russia has reportedly issued navigation warnings over possible missile firings and other activities in waters near the Kuril Islands, as well as waters off Japan's Sanriku region that include part of the country's exclusive economic zone.
Japan's Defense Minister Kishi Nobuo told reporters on Friday that the drill may be aimed at showing that Russia can conduct military activities in the Far East while invading Ukraine.
Kishi said his ministry will continue gathering intelligence and monitoring the Russian move with serious concern.