MOSCOW (AP) — Russia’s defense minister says the military forces in the country’s east have been put on high alert in the run-up to massive war games that also involve China and Mongolia.

Sergei Shoigu said the five-day drills that began Monday will pave the way for the Vostok (East) 2018 military exercise. Shoigu said those maneuvers, set for next month, will be the largest since the massive Soviet war games in 1981.

Shoigu said army, air force and navy units will take part in the exercise that will be held across the Far East and Siberia. He added that military units from China and Mongolia will also take part.

The Russian military has increased both the scope and frequency of its maneuvers amid tensions with the West.