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 Syrian presidency said the same day.

Photos showed interim Syrian President Ahmed al-Sharaa and SDF commander Mazloum Abdi shaking hands in Damascus on the agreement that provides for SDF-controled civilian and military institutions in northeast Syria to be integrated with the state.

The accord came at a critical moment as Sharaa grapples with the fallout from mass killings of Alawite minority members in western Syria — violence that he said Monday threatened his effort to unite Syria after 14 years of conflict.