Jihadists in Syria's Idlib failed to meet a Monday deadline to leave a planned buffer zone.
A Russian-Turkish truce agreement reached nearly a month ago for the northwestern region gave "radical fighters" until October 15 to leave a proposed demilitarised area between government and jihadist forces.
Turkish AKP government said Tuesday the deal with Russia to set up a buffer zone for Idlib was still on course, despite jihadists missing a deadline to withdraw. But jihadists have held their ground, with a monitoring group saying Tuesday there were still "no signs" of an evacuation.
Syria's government said it would take "time" to judge if the deal had failed.
"We have to wait for the Russian reaction. Russia is monitoring and following the situation," said Foreign Minister Walid Muallem.
Hours before the cut-off time, Idlib's jihadist Hayat Tahrir al-Sham vowed to continue attacking.
"We have not abandoned our choice of jihad and fighting towards implementing our blessed revolution," said HTS, an alliance led by Al-Qaeda' Syria branch.