MOSCOW — Russia’s military chief of staff says that the military exercises that begin next week, expected to be the biggest in three decades, will involve nearly 300,000 troops.

The Vostok 2018 exercises in central and eastern Russia will also include participants from the Mongolian and Chinese militaries.

Chief of Staff Gen. Valery Gerasimov said Thursday that the war games will include “massive” mock airstrikes and testing of measures against cruise missiles.

There will be maneuvers in the Sea of Okhotsk, which borders Russia and Japan, and in the northern Pacific, he said.

The most intensive part of the exercises will be in the Tsugol range, about 150 kilometers (90 miles) from the Chinese and Mongolian borders, where forces of those two countries will practice against Russian formations, he said.