On Tuesday, Russia launched its biggest military exercise since the Cold War and it will be involving about 300,000 service personnel in eastern Siberia.
China sent 3,200 troops to take part in "Vostok-2018", with many Chinese armored vehicles and aircraft. Mongolia is also sending some units to take part in the exercise.
It was in 1981 since Russia last held a military exercise of similar scale. The older exercise was done during the Cold War; however, Vostok-2018 has more troops participating in the event.
As the exercises began, Russian President Vladimir Putin met with his Chinese counterpart Xi Jinping at a forum in the eastern city of Vladivostok on Wednesday and told him "we have a trusting relationship in the sphere of politics, security and defense".
The Issue with NATO
Meanwhile, the relations between Russia and NATO - a 29-member defense alliance dominated by the US - have worsened since Russia annexed Crimea from Ukraine in 2014.
According to Kremlin spokesman Dmitry Peskov, the military drills were justified given the "aggressive and unfriendly" attitudes towards Russia.
Throughout Tuesday and Wednesday, the troops will be doing planning and preparation while actual operations will start on Thursday, September 13, 2018 and it will last five days as stated by the head of the Russian general staff, Gen Valery Gerasimov.
The Russian defense ministry stated that 36,000 tanks, armored personnel carriers and armored infantry vehicles will take part in Vostok-2018 from 11 to 17 September along with more than 1,000 aircraft.
The word 'Vostok' is Russian for east.
The exercise will be spread across five army training grounds, four airbases and areas in the Sea of Japan, Bering Straits and Sea of Okhotsk. Up to 80 naval vessels will take part in the naval exercises.
On the other hand, the military drills will not be near the disputed Kuril islands north of Japan according to Russian media.
The ministry's TV channel Zvezda said that three brigades of Russian paratroops will play a key role during drills at the Tsugol military range, near Russia's borders with China and Mongolia.
A key goal in the military exercise is to practice the rapid deployment of thousands of troops, as well as aircraft and vehicles, from western Russia to the eastern regions. That involves in-flight refueling of fighter jets.
The scale of Vostok-2018 is equivalent to the forces deployed in one of the big World War Two battles.
