Photo/Illutration The Russian naval fleet is spotted south of the Sea of Okhotsk. The lead vessel is an icebreaker. (Provided by the Joint Staff Office at the Defense Ministry)

Moscow apparently deployed its naval fleet of 24 warships to waters close to the Japanese archipelago this month, a move coinciding with escalating international tensions between Russia and Ukraine, Japan’s defense minister said Feb. 15.

Nobuo Kishi said the vessels had been spotted in the Japan Sea and south of the Sea of Okhotsk since Feb. 1 in what was presumed to be part of a drill by the entire Russian Navy.

“The Russian military is intensifying its activity in the east and west to show off its capability in concert with what it has been doing around Ukraine,” Kishi said at a news conference. “A large-scale military exercise by the entire Russian naval fleet at this time of the year is extremely unusual.”

He said the activity was detected by Maritime Self-Defense Force destroyers and P-3C anti-submarine and maritime surveillance. The Russian vessels ranged from destroyers and frigates to missile tracking ships and submarines.

Kishi took the opportunity to state that Japan is continuing to closely monitor the Russian military’s buildup along the Ukrainian border, which he labeled a matter of grave concern.