Russia's Pacific Fleet warship has test-fired anti-ship cruise missiles in the Sea of Japan off Vladivostok, the country's Defense Ministry said Tuesday.

Two "Mosquito" cruise missiles, developed during the Soviet era, attacked a mock enemy warship about 100 kilometers away during an exercise in the Peter the Great Gulf, according to the ministry.

Russia has released a video of the missile firings through a communication app. The nation's Tass news agency quoted the military as saying that the launches were carried out after ensuring no safety concerns in the surrounding waters.

In Tokyo, Prime Minister Fumio Kishida told reporters later in the day that Japan will "keep monitoring the moves by the Russian military," adding his government will maintain "necessary communication" with Moscow.

Japanese Foreign Minister Yoshimasa Hayashi said at a press conference that Russian forces have been "intensifying their activities also in the Far East" while Moscow continues its aggression against Ukraine.

Meanwhile, on Monday, Russian Security Council Secretary Nikolai Patrushev, a close aide of President Vladimir Putin, criticized the United States for pressing Japan to "militarize" its Self-Defense Forces in an interview with a government-controlled newspaper.

Referring to Tokyo's plan to purchase 400 Tomahawk cruise missiles from Washington, Patrushev cautioned the SDF against developing full-fledged military forces, saying it would be a "serious breach" of post-World War II norms.