The U.S. authorities have condemned Moscow actions meant against Ukraine, U.S. Department of State Spokesperson Jen Psaki said.

" We condemn Russia's increased militarization of the Donbas region through the provision of tanks and other heavy equipment to separatists. The OSCE SMM monitors have reported the movement of large military convoys of Russia-supplied heavy weapons and tanks to the front lines of the conflict in recent days, and greatly intensified shelling around the Donetsk airport in Debaltseve," she stressed.

Psaki said that separatists appear intent on making territorial gains "well beyond the lines agreed in Minsk."

"There are no excuses for these ongoing and continuous blatant violations of the Minsk protocol by Russia and its proxies," she added.