Ukrainian President Petro Poroshenko, German Federal Chancellor Angela Merkel and French President Francois Hollande insisted on the immediate ceasefire in Donbas in their telephone conversation, the Ukrainian presidential press center said.

The three leaders demand the immediate ceasefire amid "the ongoing escalation of the conflict and the growing number of civilian casualties," it said.

Besides, Poroshenko, Merkel and Hollande called for "restoring every provision of the Minsk agreement as a foundation of the peace process in Donbas," the press center continued.

The leaders of Ukraine, Germany and France agreed there must be no preconditions for convening a Trilateral Contact Group meeting.

Poroshenko, Merkel and Hollande said they were disappointed by the Contact Group's failure to make progress at its latest sitting in Minsk.

The three chiefs of state pledged to carry on close coordination of their steps towards peace in Donbas.