The Kurdish-led administration in northeastern Syria signed an agreement with the new Syrian government in March to integrate into Syria's state institutions.

The two sides are expected to meet again in Damascus "soon" to discuss the implementation of the deal, Badran Ciya Kurd, a senior official in the Kurdish-led administration, told AFP.

Kurdish-led forces took control of much of Syria's northeast, including its oil fields, following the outbreak of the country's civil war in 2011.

With support from a US-led international coalition, the Kurdish-led Syrian Democratic Forces played a key role in the Islamic State group's territorial defeat in Syria, achieved in 2019.

Ciya Kurd said the delegation will demand "a decentralised, pluralistic, democratic Syria".

"The mosaic of Syrian society cannot be governed by a political system that monopolises all powers and does not recognise the distinctiveness of regions and components," he added.

The Kurds were marginalised and repressed during decades of Assad family rule over Syria, which ended with Bashar al-Assad's overthrow in December.

Despite the March agreement, they rejected a temporary constitutional declaration announced by the Islamist-led Syrian authorities in March and said the new government failed to reflect the country's diversity, accusing it of centralising Syria's decision-making.

"This centralised thinking when managing (outstanding) issues without accepting real partnership and distributing roles and powers between the centre and the regions makes negotiations a difficult process that moves slowly," Ciya Kurd said.

This month, Syrian Foreign Minister Asaad al-Shaibani warned that "the unity of Syrian territory is non-negotiable", adding that any delays in implementing the agreement with the Kurds would "prolong the chaos" in the country.

The agreement would see see the integration of the Kurdish administration's civil and military institutions into the Damascus government.

It would also include all border crossings, the airport, as well as the oil and gas fields.

In a statement issued on Sunday, the Syrian presidency said that interim President Ahmed al-Sharaa met with US Special Envoy for Syria Tom Barrack on Saturday.

Both sides agreed on "the necessity of implementing a comprehensive agreement with the SDF, ensuring the return of Syrian government sovereignty over all Syrian territories, while discussing mechanisms to integrate these forces within state institutions", the presidency said.

Ciya Kurd said that Washington, which recently lifted its sanctions on Syria, is "among the supporters and facilitators of the ongoing negotiation process with Damascus".