The UN has sent 29 trucks of humanitarian aid to Syria's northwestern Idlib province on Tuesday.
The convoy passed through the Cilvegözü border gate in southern Hatay's Reyhanlı district.
Some 580 tons of humanitarian aid will be distributed to people in need in Idlib and its rural areas.
Located near the Turkish border, Idlib province is home to more than 3 million Syrians, many of whom fled from other cities following attacks by regime forces.
The Syrian regime had announced plans last month to launch a major military offensive to the area, long controlled by various armed opposition groups.
The UN warned that such an offensive would lead to the "worst humanitarian catastrophe in the 21st century".
On Monday, Turkish President Recep Tayyip Erdoğan and Russian leader Vladimir Putin agreed to establish a demilitarized zone in Syria's Idlib province.
