Syria's government and the Kurdish-led Syrian Democratic Forces agreed a new ceasefire on Tuesday as Washington said the SDF's purpose in fighting Islamic State group jihadists was largely over.

The announcement came after the army sent reinforcements to the Kurds' Hasakeh province stronghold in the northeast, and Kurdish forces withdrew from the Al-Hol camp which houses thousands of people with suspected IS links, including foreign women and children.

The latest truce opens the way for further talks on a deal announced on Sunday between President Ahmed al-Sharaa and SDF chief Mazloum Abdi that includes integrating the Kurds' de facto autonomous administration into the state, in a major blow to the Kurds.

The SDF once controlled vast areas of north and east Syria which it seized fighting IS with support from a US-led international coalition.

But they have now withdrawn from Arab-majority Raqa and Deir Ezzor provinces after a government military escalation that began in Aleppo earlier this month.

The defence ministry in Damascus announced a four-day ceasefire starting on Tuesday evening.

The SDF said it was committed to the truce and ready to "move forward with implementing" Sunday's agreement.

Sharaa's Islamist forces toppled long-time ruler Bashar al-Assad in 2024. The new authorities are seeking to extend state control across Syria, resetting international ties including with the United States, now a key ally.

US President Donald Trump backed Sharaa as a "tough guy" on Tuesday, adding: "But you're not gonna put a choir boy in there and get the job done."

US envoy Tom Barrack said earlier "the original purpose of the SDF as the primary anti-ISIS force on the ground has largely expired, as Damascus is now both willing and positioned to take over security responsibilities, including control of ISIS detention facilities and camps".

Syria's presidency on Tuesday announced a fresh "understanding" with the Kurds over the fate of Kurdish-majority areas of Hasakeh province, and gave the Kurds "four days for consultations to develop a detailed plan" for the area's integration.

If finalised, government forces "will not enter the city centres of Hasakeh and Qamishli... and Kurdish villages", it added. (AFP)