Moscow will start a 10-day naval exercise on Tuesday, involving dozens of ships sailing in the Pacific Ocean and waters close to South Korea and Japan, Russia's Defense Ministry said."The sailors will practice anti-submarine operations, defending ship detachments at sea, joint missile strikes against groups of ships belonging to a hypothetical enemy, training to repel drone and unmanned attacks, and perform a set of practical training and combat exercises," the ministry said in a statement.A video published by Russia's Defense Ministry showed several ships and a submarine sailing out to sea from the Far East city of Vladivostok, an operational base for Russia's Pacific Fleet.The naval drills will be held in the Pacific Ocean, Sea of Japan and the Sea of Okhotsk, involving "40 ships, boats and support vessels" as well as about 20 planes and helicopters, according to the Defense Ministry.Russia routinely carries out drills in Pacific waters off its Far East coast as a show of naval strength, but Western countries have watched them with increased anxiety since Moscow invaded Ukraine over two years ago.The drills also come ahead of a visit by President Vladimir Putin to North Korea on Tuesday.