A ceasefire in the Donbas conflict zone is a key step towards the restoration of stability, normalization and ultimately, peace, Chief Monitor of the OSCE Special Monitoring Mission to Ukraine (SMM) Ertugrul Apakan said on Tuesday.

"The Chief Monitor called on the sides to adhere to a full and sustainable ceasefire as already agreed," the OSCE press service said on Tuesday evening.

"Adherence to a full and sustainable ceasefire is a basic requirement of the Minsk documents," the report said, adding, "It is a political and moral obligation."

"As an immediate first step, withdrawal of weapons in accordance with the Minsk Agreements and disengagement are needed. These efforts would represent a significant development towards the peace the people of Ukraine need," Apakan said.