Russia has launched a week of war games involving forces from China and other nations in a show of growing defence co-operation between Moscow and Beijing as they face tensions with the US.
The manoeuvres are also intended to demonstrate that Moscow has sufficient military might for drills even as its troops are fighting in Ukraine.
The Russian Defence Ministry said the Vostok 2022 exercise will be held until 7 September at seven firing ranges in Russia's Far East and the Sea of Japan, and will involve more than 50,000 troops and 5,000 weapons units, including 140 aircraft and 60 warships.
Russian General Staff chief General Valery Gerasimov will personally oversee the drills that will involve troops from several ex-Soviet nations, China, India, Laos, Mongolia, Nicaragua and Syria.
The Defence Ministry said the Russian and Chinese navies in the Sea of Japan will "practise joint action to protect sea communications, areas of marine economic activity and support for ground troops in littoral areas".
The drills showcase increasing defence ties between Moscow and Beijing, which have grown stronger since Russian president Vladimir Putin sent his troops into Ukraine on 24 February.
Watch: West needs to 'wake up' to threat of Russia-China alliance, Ellwood says.
China has refused to criticise Russia's action, blaming the US and NATO for provoking Moscow, and has criticised punishing sanctions imposed on Moscow.
Russia has strongly backed China amid the tensions with Washington that followed a recent visit to Taiwan by US House of Representatives speaker Nancy Pelosi.
Mr Putin has drawn parallels between US support for Ukraine and Ms Pelosi's trip, describing them as part of alleged efforts by Washington to stir up global instability.
Alexander Gabuyev, a political analyst, said: "It's very important for Beijing to show to the US that it has levers to pressure America and its global interests.
"The joint manoeuvres with Moscow, including the naval drills, are intended to signal that if the pressure on Beijing continues it will have no other choice but to strengthen the military partnership with Russia. It will have a direct impact on the interests of the US and its allies, including Japan."
He added that the Kremlin wants to show that the country's military is powerful enough to flex its muscle elsewhere despite the campaign in Ukraine.
Watch: How the Ukrainian counter-offensive against Russia is supported.
The exercise continues a series of joint war games by Russia and China in recent years, including naval drills and patrols by long-range bombers over the Sea of Japan and the East China Sea.
Last year, Russian troops for the first time deployed to Chinese territory for joint manoeuvres.
China's participation in the drills "aims to deepen pragmatic and friendly co-operation between the militaries of the participating countries, enhance the level of strategic co-operation among all participating parties, and enhance the ability to jointly respond to various security threats", the Chinese Defence Ministry said last week.
Mr Putin and Chinese President Xi Jinping have developed strong personal ties to bolster a "strategic partnership" between the former communist rivals as they are locked in rivalry with the US.
Even though Moscow and Beijing in the past rejected the possibility of a military alliance, Mr Putin has said such a prospect cannot be ruled out.
He also has noted that Russia has been sharing highly sensitive military technologies with China that helped significantly bolster its defence capability.