The operations against pro-Russian militants have been suspended over Easter, said Ukrainian Foreign Minister.

As he told the BBC, the security services would resume military action if the separatists continued to occupy government offices. They are refusing to leave buildings in several cities, defying an agreement reached on Holy Thursday to defuse the crisis.

In the meantime, U.S. threatened Russia with new sanctions if it does not convince the separatists to surrender, although Moscow continues to deny US accusations of fomenting violence in Eastern Ukraine.