Ukraine's Prime Minister has claimed Russia has special forces in eastern Ukraine in a deliberate attempt to undermine upcoming presidential elections.
Arseniy Yatsenyuk also again called on the Kremlin to withdraw Russian troops from Crimea and "turn this shameful page" in relations between the two countries.
Tensions remain high in eastern Ukraine after at least three died in a day of shooting during what was supposed to be an Easter truce.
In an exclusive interview with NBC News, the Ukrainian Prime Minister warns of the dangers of unchecked Russian expansion and aggression.
Russia, the US and the EU say that all sides have agreed to steps to "de-escalate" the crisis in Ukraine at talks in Geneva.