Syria's Islamist-led government on Monday said it had completed a military operation against a nascent insurgency by Bashar al-Assad loyalists, as it faced Western demands for accountability over the reported killing of hundreds of civilians.

The commander of a Kurdish-led force in Syria said on Sunday the country's interim president must hold the perpetrators of communal violence in Syria's coastal areas to account, accusing Turkey-backed factions of being primarily behind the killings.

Syria's new leader has vowed accountability and an investigation after reports of mass killings of Alawite civilians triggered an international backlash against the worst violence since Bashar al-Assad's overthrow.

The Kurdish-led and U.S.-backed Syrian Democratic Forces, which controls much of Syria's oil-rich northeast, signed a deal with the Damascus government on Monday to join Syria's new state institutions,

The government in Damascus led by Islamist former rebel group Hayat Tahrir al-Sham (HTS) had been calling on the SDF and other armed groups that formed during the 13-year civil war to integrate under the command of the new Defense Ministry, but an agreement with the Kurdish-led force was elusive until now.

The agreement was signed by Syrian President Ahmed al-Sharaa and Mazloum Abdi, the commander of the Kurdish-led Syrian Democratic Forces.