"I welcome the agreement held between President Erdogan and Russian President Putin on the creation of a weapons-free buffer zone in Idlib. When this agreement will properly be implemented, it could save 3 million civilians, including 1 million children," Guterres said.

Turkey and Russia agreement

Turkey and Russia agreed to turn Syria's northwestern Idlib province into a demilitarized zone.

"We have agreed on the establishment of a weapons-free zone between the opposition- and [Assad] regime-controlled areas," Turkish President Recep Tayyip Erdogan said in a news conference with his Russian counterpart Vladimir Putin in the Black Sea coastal city of Sochi, following a meeting between the two leaders.