North Atlantic Treaty Organisation spokesperson Dylan White said that the military organization has been briefed about the exercise in May and it would monitor it. "Vostok demonstrates Russia's focus on exercising large-scale conflict".
President Vladimir Putin is expected to attend the war games after hosting an economic forum in Vladivostok where Chinese leader Xi Jinping is one of the guests.
Shoigu said that about 300,000 military personnel would take part, twice as many as the largest war games conducted by the Soviet Union: the Zapad-81 exercises in 1981.
The activity was part of the first stage of the exercise, which runs until Monday next week, the ministry said in a statement.
The last war games in Vostok were in 2014 but were nearly half of the size with 155,000 soldiers taking part.
"The fact that the last thing Europe and the United States want is any open conflict with Russian Federation is immaterial - it may take two to tango, but it doesn't take two sides to start a war".
Russian Federation has substantially increased the size and frequency of its military exercises in recent years, particularly following its invasion of Crimea in 2014.
Dmitri Trenin, a former Russian army colonel and director of the Carnegie Moscow Center think tank, said: "With its Vostok 2018 exercise Russia sends a message that it regards the United States as a potential enemy and China as a potential ally".
Last month, Kremlin spokesman Dmitry Peskov said Russia's "ability to defend itself in the current global situation which is often aggressive and unfriendly to our country is justified, essential and without alternative".
China's official People's Liberation Army Daily said on Wednesday that the drill was aimed at maintaining regional peace, was not aimed at any third party and did not "have anything to do with the regional situation".
The latter comprise six Mi-171s, which were bought from Russian Federation in 2014 and are making their first appearance in such an exercise, nine Z-9s and nine Z-19s.
Experts said in reality neither China or Russian Federation believe the two are close to a full-fledged military alliance, but the joint drills nonetheless reflected how much more cooperative the two countries' relationship has become, after decades of suspicion during the Soviet period.
The war games are held a year after Russian Federation staged major drills in the country's west last September, unnerving neighbouring former Soviet republics.
The week-long war games dubbed "Vostok-2018" (East-2018), "have kicked off" in far eastern Russian Federation and on the Pacific Ocean, the defense ministry said in a statement.
Tanks roll during the military exercises in Chita, Eastern Siberia, during the Vostok 2018 exercises, September 11, 2018.
He added: "Russia also thinks that the worldwide reactions to its appalling behaviour over recent years - including the seizure of Crimea, aggression against Ukraine, causing and abetting untold suffering in Syria, the attempted murder of the Skripals and more - are just more indications of this "aggressive and unfriendly" attitude by the rest of the world".
He said that an increasingly unpredictable geopolitical climate made partnership between Russian Federation and China particularly important.
Named Vostok-2018, the rehearsals aim to check the readiness of the Russian armed forces.