"I am glad of the truce agreed to the beginning of the academic year in the east of Ukraine and I call on the parties to observe it, to continue working on the implementation of the Minsk agreements," Kurtz wrote on Twitter.
He also noted that the OSCE is carrying out important work.
Earlier in the OSCE, they stated that they had recorded more than 70 violations of the "school armistice" in the Donbass.