Russian Federation began its biggest war games since the fall of the Soviet Union on Tuesday close to its border with China, mobilising 300,000 troops in a show of force that will include joint exercises with the Chinese army.
Moscow said the weeklong manoeuvrers, known as Vostok (East) 2018, would span vast expanses of Siberia and the Far East, the Arctic and the Pacific Ocean and involve nearly a third of Russia's million-strong military.
The military exercises come at a time of escalating tensions between Moscow and the West over accusations of Russian interference in western affairs and ongoing conflicts in Ukraine and Syria.
The main aim was to check the military's readiness to move troops large distances and test how closely infantry and naval forces cooperated. If we recall the "Zapad 2017", simultaneously with this event Russian Federation conducted its exercises coordinated with the "Zapad" on its territory.
The previous Russian exercise involving a similar scale was in 1981 during the Cold War, but there are more troops in Vostok 2018.
At sea, the Russian fleet is deploying several frigates equipped with Kalibr missiles that have been used in Syria.
Russian Defence Minister Sergei Shoigu has described the drills as even bigger than the country's largest Cold War-era exercise - Zapad 1981 - that put North Atlantic Treaty Organisation allies on edge.
Russian officials have said that the war games are not meant as a threat to any particular country but are justified by what Putin's spokesman described on August 28 as a hostile worldwide environment.
Russia's latest hardware is being showcased during the war games, including its Iskander missiles that can carry nuclear warheads, the T-80 and T-90 tanks and its new Su-34 and Su-35 fighter planes.
"Cooperation in traditional security fields between China and Russian Federation has a very clear target [the United States]", he said.
Mongolia has also sent a military contingent. It is emphasized that they will be the largest military exercises in the last 37 years.
She added: "China has growing military capabilities and is playing an increasingly significant global role".
Shoigu said the drills "will be unprecedented in terms of geographic scope and the strength of command and control centers and forces due to participate".
Russian Federation has said it is showcasing methods developed during its military intervention in Syria, giving Chinese forces - which haven't fought in a war since 1979 - a glimpse of real combat skills.