Russia plans to hold massive war games involving 300,000 personnel next month – its biggest military manoeuvres since the Cold War.
Defence Minister Sergei Shoigu said units from China and Mongolia would take part in the exercise, at military ranges in central and eastern Russia.
He compared the “Vostok-2018” war games to Soviet manoeuvres in 1981, which involved a pretend attack on Nato.
The exercises come at a time of rising tension between Nato and Russia.
Nato reacted to Russia’s annexation of the Crimea from Ukraine in 2014 and its backing of pro-Russian rebels in eastern Ukraine with an increased deployment of forces in eastern Europe.
Russia says the Nato build-up is unjustified and provocative.
What will take place in the drills?
Mr Shoigu said 36,000 tanks, armoured personnel carriers and armoured infantry vehicles would take part in Vostok-2018, from 11 to 15 September, along with more than 1,000 aircraft. “Vostok” is Russian for “east”.
Referring to the Soviet manoeuvres in 1981, he said: “In some ways they will repeat aspects of Zapad-81, but in other ways the scale will be bigger.”
He said the involvement of Chinese units showed Russia and Beijing were co-operating in all areas.
Paratroops and Northern Fleet naval forces will also take part. Russia’s armed forces are reckoned to have about one million personnel in total.
The scale of Vostok-2018 is equivalent to the forces deployed in one of the big World War Two battles.
A smaller-scale Russia-Belarus exercise was held in western regions last year.
President Vladimir Putin has made military modernisation – including new nuclear missiles – a priority.
What has Nato said?
Spokesman Dylan White said Nato was briefed on Vostok-2018 in May and would monitor it.
He said the organisation was considering a Russian offer to allow Nato military attachés based in Moscow to be sent to observe the drills.
He said in a statement: “All nations have the right to exercise their armed forces, but it is essential that this is done in a transparent and predictable manner.”
He added: “Vostok demonstrates Russia’s focus on exercising large-scale conflict. It fits into a pattern we have seen over some time: a more assertive Russia, significantly increasing its defence budget and its military presence.