The Russian Federation has about 82,000 regular troops deployed along the border with Ukraine, as well as in occupied Donbas, eastern Ukraine, and Crimea, a peninsula it annexed from Ukraine in March 2014.

"These are active troops that can immediately increase their numbers during unforeseen military activities," chief of the Verification Department of the General Staff of the Ukrainian Armed Forces Andriy Hudz said at a briefing, according to an UNIAN correspondent.

Read alsoIntelligence chief says Ukrainian military may open fire at enemy without order

Now, there are more than 25 battalion task groups in Russia's Rostov region along the state border of Ukraine, the 150th motorized rifle division is being actively formed there, he said.

The groups deployed in Russia-occupied territory of Ukraine are managed by the tactical headquarters based in Rostov region's Novocherkassk, which is part of the Southern Military District.

"The said military bodies are outside the control of the OSCE and other security organizations," he added.

According to the Ukrainian General Staff, Russia has doubled its military presence on the Crimean peninsula since 2014.

"The deployment by Russia of missiles with nuclear warheads, including the Iskander ground-based systems and Kalibr-type ship-launched systems whose range may exceed the limits defined by the Treaty on the Elimination of Their Intermediate-Range and Shorter-Range Missiles poses a threat," he said.

Russia is also trying to conceal the presence of newer aircraft in Crimea, such as Yak-130, MiG-29, Su-30M and Mi-35M, as well as Mi-24 helicopters, Hudz added.