TOKYO (AP) — Japan’s government said Thursday it is closely watching military activities by Russia following reports it conducted tests of submarine-launched missiles in the Sea of Japan, in its latest military exercises off the Japanese coast following its invasion of Ukraine.

The missile tests came a day after the U.S. Navy’s 7th Fleet and Japan’s Maritime Self-Defense Force announced joint naval exercises in the Sea of Japan.

Russia’s ITAR-Tass news agency reported that two diesel-powered submarines from the Russian Pacific Fleet successfully launched Kalibr cruise missiles at a naval target during the exercises Thursday. Japanese media carried similar reports.

Tass said the target was a ship structure simulating an enemy vessel, and the exercise involved more than 15 warships from its Pacific Fleet and warplanes.

The Kalibr cruise missile is designed to fly at subsonic speeds and can hit targets as far as 2,000 kilometers (1,200 miles) away, Tass said.

“Russia has escalated its military activities by deploying its latest equipment and conducting exercises and training around Japan,” Japanese Chief Cabinet Secretary Hirokazu Matsuno said. He said Japan is closely watching Russian activity, but would not give further details, saying “doing so would reveal Japan’s information gathering capability.”


In late March, Russia held large military drills involving 3,000 troops on islands that are also claimed by Japan, prompting a protest from Tokyo.

The dispute over the islands, which Moscow seized at the end of World War II, has prevented the two countries from signing a peace treaty formally ending their wartime hostilities. In apparent retaliation for Japan’s imposition of sanctions against Russia for its invasion of Ukraine, Moscow announced it will discontinue talks on a peace treaty with Tokyo.

On Wednesday, the U.S. 7th Fleet and Japan’s Maritime Self-Defense Force said they are conducting their first joint naval exercises in the Sea of Japan since 2017.

The exercises, led by the USS Abraham Lincoln aircraft carrier strike group, apparently are a demonstration of the two nations’ close military alliance amid growing speculation of a North Korean missile or nuclear test as early as this week. Friday is the 110th birthday of late North Korean founder Kim Il Sung and is the country’s most important anniversary.