Russia's Defence Ministry said Thursday that large-scale military exercises had started in southern Russia and in disputed territories on Russia's borders.
The exercises involve more than 2,000 anti-aircraft troops and 500 items of weaponry and will last until April 10, the Interfax news agency reported.
The Defence Ministry said the exercises were taking place in Russia's Southern and North Caucasus Federal Districts, as well as on Russian military bases in Armenia, the Georgian separatist regions of Abkhazia and South Ossetia and Ukraine's Crimea region, which Moscow annexed last year.
They are likely to be viewed in the West as a show of force as relations between Russia and the West are at their most strained since the Cold War because of the Ukraine crisis.
Ukraine and the West accuse Russia of directing a separatist assault in eastern Ukraine with its own troops and weapons. Russia has repeatedly denied those accusations.
At a news conference in Moscow unrelated to the exercises, Russian Deputy Defense Minister Anatoly Antonov said NATO activities on Russia's borders far exceeded anything the Russian military was undertaking.
"NATO states are using the situation in the south-east of Ukraine as an excuse to … move forward, closer to Russia's borders," Interfax quoted Antonov as saying.
On Wednesday, a NATO flotilla arrived in the Black Sea to train with ships from the Bulgarian, Romanian and Turkish navies, the defence alliance said.