Requesting anonymity, the Kurdish source with knowledge of the talks between Sharaa and Abdi said differences concerned “the mechanism for implementing the terms of the agreement”.
Despite the ceasefire, brief clashes erupted on Monday evening (local time) in Raqqa city, with an AFP correspondent hearing heavy bombardment.
Using another name for the Islamic State group, the SDF said government forces shelled the Al-Aqtan prison “which holds Isis members and leaders, in an attempt to storm it”.
Raqqa was once the jihadist group’s de facto capital in Syria.
A defence ministry source later told AFP that the clashes had halted, without elaborating.
‘Stability’
Sunday’s agreement included the Kurdish administration’s immediate handover of Arab-majority Deir Ezzor and Raqqa provinces to the Government, which will also take responsibility for IS prisoners and their families held in Kurdish-run jails and camps.
A defence ministry map published on Monday showed the Government controlled all of Deir Ezzor and Raqqa provinces, while the eastern parts of Hasakeh province were still under Kurdish control.
In Deir Ezzor province, an AFP correspondent saw military vehicles heading east of the Euphrates, while cars and pedestrians waited at a bridge leading to the eastern bank.
Driver Mohammed Khalil, 50, told AFP that “we hope things will be better than before. There was ... no freedom” under the SDF.
Teacher Safia Keddo, 49, said that “we’re not asking for a miracle, we just want stability and a normal life”.
Authorities announced a curfew in Hasakeh province’s Shadadi after the army said the SDF released IS detainees from the town’s prison, while the Kurds said they lost control of the facility after an attack by Damascus.
The sides had earlier traded blame for attacks that the military said killed three soldiers.
The SDF had seized swathes of Deir Ezzor and Raqqa provinces as they expelled IS during Syria’s civil war, supported by an international coalition led by Washington.
‘Protecting civilian lives’
The AFP correspondent in Raqqa said residents toppled a statue of a woman erected by Kurdish forces.
Raqqa resident Khaled al-Afnan, 34, said “we support Kurdish civil rights ... but we don’t support them having a military role”.
Turkish President Recep Tayyip Erdogan, a close ally of Damascus who is hostile to the SDF, hailed Syria’s army for its “careful” offensive despite what he called “provocations”.
EU foreign policy chief Kaja Kallas instead said “all military activities must cease immediately”.
The SDF on Sunday withdrew from areas under its control including the Al-Omar oil field, the country’s largest, and the Tanak field.
Local fighters from tribes in the Arab-majority Deir Ezzor province sided with Damascus and seized the areas before the arrival of Government forces.
Some Arab tribes were previously allied with the SDF, which included a significant Arab component.
The SDF’s Abdi said Sunday he agreed to the deal to avoid civil war and end a conflict “imposed” on the Kurds.
Mutlu Civiroglu, a Washington-based analyst and expert on the Kurds, said the Government’s advance had raised “serious doubts about the durability” of the ceasefire and a March agreement between the Government and the Kurds.
Sharaa had on Friday issued a decree granting the Kurds official recognition, but the Kurds said it fell short of their expectations.
In Qamishli, the main Kurdish city in the country’s northeast, activist Hevi Ahmed, 40, said Sunday’s deal was “a disappointment after years of hope that the Syrian constitution might contain a better future for the Kurds”.
- Agence France-Presse