Russia cannot introduce its peacekeeping troops in Ukraine unilaterally, Andriy Lysenko, a spokesman for the Ukrainian National Security and Defense Council, has said.

"The introduction of peacekeepers is the strict prerogative of the UN (United Nations) Security Council. If a decision is made to introduce peacekeepers to any part of Ukraine, there should be a condition: it must be accepted by both parties to the conflict. So far there has been no UN statement, no consent from either party," Lysenko said at a Monday briefing.

"So intentions remain intentions," he added.

He also said that what is going in Ukraine is not a civil but a liberation war. "We are liberating our territory from bandits and terrorists," he said.

U.S. congressmen have already proposed that the self-proclaimed Donetsk and Luhansk people's republics should be recognized as terrorist organizations, he said.

Such recognition will lead to "a number of compulsory statutory acts for all the countries which have united in the fight against international terrorism," he said.