Hayat Tahrir al-Sham, a Takfiri alliance also known as al-Qaeda in Syria, said on Sunday it had adopted its stance after taking time for “consultation”.
Although it did not explicitly say it would abide by the deal, it said it would seek to provide security for people in the area it controls, Reuters reported.
“We value the efforts of all those striving - at home and abroad - to protect the liberated area and prevent its invasion…,” Tahrir al-Sham said in a statement.
“But we warn at the same time against the trickery of the Russian occupier or having faith in its intentions,” it added.
Idlib’s other main rebel faction, the so-called National Liberation Front, a Turkish-backed militant alliance in Idlib, has already expressed its support for the agreement.
The deal sets up a demilitarized zone running 15-20 km (9-13 miles) deep into rebel territory that must be evacuated of all heavy weapons and all terrorist groups by Monday, Oct. 15.
Turkish President Recep Tayyip Erdogan reached an accord with his Russian counterpart Vladimir Putin on September 17, under which all militants in the planned buffer area must hand over their heavy weapons and terrorist groups must withdraw.