Russia's previous military exercise in the region, Vostok-2014, was nearly half the size, with 155,000 soldiers participating. The forthcoming summit will reportedly be held in part of an economic forum which in turn will take place in Vladivostok, a city in Russia's far eastern region.
Nor would they enlighten reporters as to why there was no sign of the more than 3,000 Chinese soldiers sent to the maneuvers by Beijing.
"We have trustworthy ties in political, security and defence spheres", the Russian leader said.
The five-day games kicked off simultaneously at five of the designated training grounds located around the Far East Russian region as well as in the maritime areas such as that of the East Sea (Sea of Japan) and the Bering Sea.
But Russia's defence minister, Sergei Shoigu, said these exercises were even larger.
He said that an increasingly unpredictable geopolitical climate made partnership between Russian Federation and China particularly important.
Chinese military vehicles through a field in Chita, Eastern Siberia, during the Vostok 2018 exercises, September 11, 2018.
The People's Liberation Army, China's military, was "still in the process of acquiring combined arms training and expertise as it transformed into an informationised and modern fighting force", he said. "If Russia had not invited China, that would have been viewed by Beijing as a potentially unsafe activity by Russia".
Kremlin spokesman Dmitry Peskov said the drills were compulsory to safeguard itself amid the present global condition which is quite belligerent and antagonistic.
But according to Keir Giles, a Russian military expert at the UK-based Chatham House think-tank, the overall aim of the drill is to "prepare Russia for armed conflict with the West". "The enemy is the United States and its allies".
Vostok 2018 will take place at a time of increasing tensions between the West and Russian Federation, which is perturbed about the promotion of the North Atlantic Treaty Organisation military league on its western flank.
The Chinese military has joined hundreds of thousands Russian troops to take part in the nation's largest ever war games - a powerful show of burgeoning military ties between Moscow and Beijing amid their tensions with the US.
"In some ways (Vostok-2018) will repeat aspects of Zapad-81, but in other ways the scale will be bigger", Shoigu said.