Russian warships set off Monday to take part in joint naval drills with China, an exercise that showcases increasingly close defence ties between the two countries as they face tensions with the United States.

The Russian Defence Ministry said the Varyag missile cruiser, the Marshal Shaposhnikov destroyer, and two corvettes of Russia’s Pacific Fleet would take part in manoeuvres in the East China Sea starting Wednesday.

The ministry said the Chinese navy planned to deploy several surface warships and a submarine for the exercise. Russian and Chinese aircraft will also take part in the drills, according to the ministry.

Moscow and Beijing have displayed their growing military cooperation in recent months.

In November, Tu-95 bombers of the Russian air force and Chinese H-6K bombers flew joint patrols over the Sea of Japan and the East China Sea. As part of the drills, the Russian bombers landed in China for the first time, and the Chinese bombers flew to an air base in Russia.

In September, China sent more than 2000 troops, more than 300 military vehicles, 21 combat aircraft and three warships to take part in a sweeping joint exercise with Russia. The manoeuvres marked the first time that China sent forces from three branches of its military to take part in a single Russian drill, in what was described as a show of the breadth and depth of China-Russia mutual trust.

Defence cooperation between Moscow and Beijing has grown stronger since Russian President Vladimir Putin sent his troops into Ukraine on February 24.

China, which has declared a “no limits” friendship with Russia, has pointedly refused to criticise Moscow’s actions, blaming the US and Nato for provoking the Kremlin, and has blasted the punishing sanctions imposed on Russia.

Russia, in turn, has strongly backed China amid the tensions with the US over Taiwan.