Tribal figures linked to a US-backed alliance announced plans Monday for a council to run Syria's Deir Ezzor, as both the alliance and regime troops battle militants in and around the city.
Held by the Islamic State group, the city is the capital of the eastern province of Deir Ezzor, regarded as a strategic prize by both Syrian troops and the US-backed Syrian Democratic Forces.
With Russian backing, Syrian regime forces have seized western parts of the province and breached IS's years-long siege on parts of the city.
SDF fighters are waging a separate offensive that has captured swathes of territory from IS east of the Euphrates River, which cuts across the province.
The SDF has not reached Deir Ezzor city itself, but on Monday its media office said a "preparatory committee" would begin laying the groundwork for a civil council to run the city after IS's defeat.
Local figures would announce "the preparatory committee of the Deir Ezzor Civil Council and the support of the tribes for the SDF," the media office said in a statement.
It remained unclear whether the Deir Ezzor Civil Council would coordinate with, or rival, government authorities already present in other parts of the city.
Since 2014, IS has held swathes of the province and about 60 percent of its capital, encircling two regime-held enclaves in the western half of Deir Ezzor city.
Government troops have broken both militants sieges and were preparing on Monday to launch an offensive on the eastern districts still held by IS.
"Military reinforcements have been arriving since Sunday night to begin the operation to seize control of the city," said Rami Abdel Rahman, who heads the Britain-based Syrian Observatory for Human Rights monitoring group.
He said the SDF had advanced to six kilometres (four miles) from the eastern banks of the Euphrates River across from Deir Ezzor city.
The SDF's advance is backed by the US-led coalition battling IS in Iraq and Syria since 2014.
The coalition, the SDF, Syria's government and Russia have agreed on a "de-confliction line" in northeastern Syria to prevent the two offensives from clashing.