At least 33 Turkish soldiers have been killed in an air strike by Syrian "regime forces" in north-western Syria, a senior Turkish official has said.

Thirty-five soldiers injured in the attack have been evacuated to hospitals in Turkey, Dogan said.

A security meeting is being held at the presidential palace after the "nefarious attack against heroic soldiers in Idlib who were there to ensure our national security," according to a statement from Turkish director of communications Fahrettin Altun.

Turkey has retaliated in an effort to "revenge our martyred heroic soldiers," the statement said.

Turkish Foreign Minister Mevlut Cavusoglu spoke to NATO Secretary General Jens Stoltenberg following the Syrian attack, according to a statement released by the ministry. There were no further details about the content of the call.

The Syrian government has not commented on the Turkish claim.