Russian Foreign Ministry spokesman Alexander Lukashevich said on Friday that his country is very concerned over reports the United States intends to provide advanced military hardware to Kiev, Itar Tass reported.

"Of particular concern are reports of the US intentions to hand over advanced military hardware to Kiev directly or through mediators," Lukashevich said.

The diplomat pointed out that the just started crash courses for Ukrainian military at a proving ground near Lviv "merely pour oil on the fire of the intra-Ukrainian armed conflict."

The Ukraine Freedom Support Act adopted by the US Congress late last year allows and even encourages such supplies, Lukashevich reminded.

Around 300 US paratroopers arrived in western Ukraine’s Lvov on April 17 to train Ukrainian servicemen to conduct combat actions, Kiev’s military operation spokesman, Andrey Lysenko, said.