The entire Russian Pacific fleet was put on high alert on Friday for snap drills that will involve practice missile launches in a massive show of force amid the tensions with the west over the fighting in Ukraine.
Defence minister Sergei Shoigu said the goal of the war games was to test the capability of Russia’s armed forces to mount a response to aggression.
Along with the missile launches, the drills will also involve nuclear-capable strategic bombers and other warplanes besides those from the Pacific fleet’s air arm, Mr Shoigu said.
The Russian military has concentrated the bulk of its forces on the front lines in Ukraine, but also continued conducting regular drills across Russia to train its forces and demonstrate their readiness.
Kremlin spokesman Dmitry Peskov described the war games as part of regular training intended to “maintain the necessary level of the armed forces’ readiness”.
Mr Shoigu said the scenario for Friday’s manoeuvres envisages a response to an adversary’s attempt to make a landing on Sakhalin Island and the southern Kuril Islands.
Japan asserts territorial rights to the Kuril Islands, which it calls the Northern Territories.
The Soviet Union took them in the final days of the Second World War and the dispute has kept the countries from signing a peace treaty formally ending their hostilities.
Last year Russia announced it had suspended peace talks with Japan in protest at Tokyo’s sanctions against Moscow over its action in Ukraine.
Russia has built up its military presence on the islands in recent years, deploying advanced fighter jets, anti-ship missiles and air defence systems there.
The Pacific fleet drills started days before a planned trip to Moscow by Chinese defence minister general Li Shangfu.
A three-day visit to Moscow by Chinese President Xi Jinping last month demonstrated the two nations’ partnership in the face of western efforts to isolate Russia over Ukraine.
Both Moscow and Beijing have accused Washington of trying to isolate them and to hold back their development as they challenge the US for regional and global leadership.
Russian President Vladimir Putin and Mr Xi said they would increase contacts between their militaries and stage more joint sea and air patrols and drills, but there was no hint that China would help Russia with weapons, as the US and other Western allies feared.