ANKARA — Turkish President Recep Tayyip Erdogan said on Tuesday that the Syrian government must engage in a political process with rebel groups to prevent further deterioration of the situation in Syria, as Turkish Foreign Minister Hakan Fidan is expected to meet with his Iranian and Russian counterparts as part of a three-party de-escalation mechanism between the countries. 

Erdogan conveyed the message during separate phone calls with Russian President Vladimir Putin and Iraqi Prime Minister Mohammed Shia al-Sudani amid ongoing clashes between Syrian government forces and Syrian insurgents. As part of their nearly week-old offensive, Islamist group Hayat Tahrir al-Sham and its Turkish-backed rebel allies have made major territorial gains, including seizing control of the civil war-torn country’s second-largest city of Aleppo. 

Turkey considers HTS a terrorist organization, but Ankara is the main backer of the Syrian armed opposition groups that also joined the offensive. Meanwhile, Russia and Iran are the main international backers of the Syrian government. 

“The Syrian regime must engage in a real political process to prevent the situation from getting worse,” Erdogan told Sudani, according to a Turkish readout of the call.