China’s military reportedly joined large-scale Russian drills on Monday in southern Russia, part of the two nations’ continued efforts to increase their military cooperation.

Russia launched its “Kavkaz 2020,” or Caucasus 2020 drills, on September 21. The event is held every four years in the country’s Southern Military District. This year, the exercises are taking place in the North Caucasus, as well as in the Black and Caspian Seas.

A total of 80,000 personnel — including 1,000 troops from China, Belarus, Armenia, Pakistan, and Myanmar — will participate in the drills this year, meant to focus on “defensive tactics, encirclement, and battlefield control and command,” Radio France Internationale (RFI) reported. Iranian warships will also take part in the sea drills.

The exercises will mobilize “[u]p to 250 tanks, up to 450 infantry fighting vehicles and armored personnel carriers, up to 200 artillery systems, and multiple launch rocket systems,” according to a statement by the Russian Defense Ministry. The drills will also “deploy wheeled vehicles and light weaponry to be flown to out by China’s latest transport aircraft,” according to RFI.

China’s People’s Liberation Army (PLA) sent personnel and weaponry to Russia’s Southern Military District this month in preparation for the event.

“Two military transport aircraft Y-20 of the Chinese air force with soldiers of the People’s Liberation Army of China arrived in the Astrakhan region to participate in the maneuvers ‘Kavkaz-2020,'” Russia’s Defense Ministry announced on September 11.

“The unit that arrived in the Russian Federation includes about 100 military personnel and military equipment of the Chinese army. Earlier, an advanced group of Chinese officers was met at a military airfield in the Astrakhan region,” the ministry said.

While China has participated in Russian military exercises in Siberia and its Far East region in the past, this year marks the first time the Asian giant has joined Russian exercises in the country’s south, over 3,100 miles from Beijing.

Moscow and Beijing established a “comprehensive strategic partnership” two decades ago and have maintained cooperation on military concerns and diplomacy since then. Last year, the two powers agreed to upgrade the terms of their strategic pact. Observers view the alliance as an effort to counter U.S. influence in Asia. The Russian and Chinese armies hold regular joint exercises and support each other on the international stage at the U.N. on issues concerning Syria and North Korea.

“As part of Russia’s military cooperation [with China], it has assisted in the development of a Chinese anti-ballistic missile early-warning system,” RFI reported.

“Kavkaz 2020” will continue through September 26.