The warring sides in the eastern Ukraine conflict have called for a cease-fire on Sept. 1, the day that the new school year is to begin.

Speaking after a meeting of the Trilateral Contact Group in the Belarusian capital Minsk, OSCE representative Martin Sajdik said Wednesday that the sides "agreed to jointly verify the fulfillment of this initiative."

The group, which is seeking an end to the conflict that has killed more than 6,400 people, includes representatives from Ukraine, the Organization for Security and Cooperation in Europe, and Russia. Representatives of the Russia-backed eastern Ukraine separatist rebels also take part.

Comprehensive cease-fires have been declared twice over the past year, but have been widely violated.