KIEV, June 25, 5:55 /ITAR-TASS/. Ukraine's President Pyotr Poroshenko on Tuesday discussed the peaceful settlement plan in telephone conversations with US Vice-President Joseph Biden, German Chancellor Angela Merkel, and Thorbjoern Jagland, Secretary-General of the Council of Europe.

Poroshenko conferred with the chiefs of security organizations. During the meeting he did not rule out a cancellation of the ceasefire regime in Ukraine's east earlier than planned.

The presidential press service reported on Tuesday, "The Head of State does not rule out that the ceasefire regime may be cancelled ahead of time in view of a continuous violation of it".

The press service maintains that Volunteer Corps membrs, "contrary to the promises made in Donetsk to observe the ceasefire regime", "shot down a helicopter of Ukraine's armed forces", which entailed the death of nine people.

The press service report asserted that since the moment when President Poroshenko announced his peace plan, security personnel were fired upon 35 times. In view of that, "in the evening of June 24, during a meeting with the chiefs of security organizations, Poroshenko issued an order to return the fire without hesitation," a press service official said.