The Easter truce between Ukrainian forces and pro-Russian separatists has come to an end, the Ukrainian government has announced.
Deputy Prime Minister Vitaliy Yarema said the government would now move to eliminate militant separatist groups who are holding public buildings in the east of Ukraine "in the near future".
Mr Yarema also said Kiev hoped for "more substantive" help from the United States in the event of any Russian aggression.
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.