Russia and China are holding a large-scale joint military exercise in north-central China involving more than 10,000 troops, Russia's defence ministry said on Tuesday.
The Sibu/Cooperation-2021 drills in China's Ningxia region are being watched for signs that China and Russia are expanding military cooperation as they spar with the West.
Russia's Kommersant newspaper said the drills taking place until Friday marked the first time Russian soldiers would use Chinese weapons. Russia and China have conducted drills since 2005.
Moscow sent Sukhoi Su-30SM fighter aircraft, motorised rifle units and air defence systems to the exercise that was focused on counter-terrorism, the defence ministry said in a statement.
The drills come as the Taliban has gained ground in Afghanistan where security has deteriorated as the United States withdraws its troops after two decades of war, creating a security headache for Moscow.
Separately, Russia on Tuesday completed joint drills in Tajikistan with Uzbek and Tajik forces near the Afghan border. Moscow also said it was bulking up its military base in Tajikistan with assault rifles and other weapons.
Moscow pivoted to China in 2014 as its political ties with the West sank to post Cold-War lows over the annexation of Crimea from Ukraine. China is Russia's biggest trade partner.