The Kurdish-led administration in northern Syria has set dates for local council and regional assembly elections, an official said on Saturday, in an apparent move to consolidate its growing autonomy.

Kurdish groups and their allies control swathes of northern Syria in areas held by the US-backed Syrian Democratic Forces (SDF), an alliance of militias spearheaded by the Kurdish YPG.

But formal self-government by the Kurds there alarms Turkey, which regards the YPG and the dominant Syrian Kurdish political party as extensions of the Kurdistan Workers' Party, or PKK, which has waged a three-decade-long insurgency against Ankara.

Elections will be held in late summer for bodies running local communities, in November for bodies running larger areas and next January for the region as a whole, the Kurdish official said via a social networking feed.

The dates and rules for conducting the vote were agreed by a council set up in December to form governing institutions and prepare for elections.

The dominant Kurdish groups in northern Syria have carved out self-governing regions since early in the civil war, but they say they are not seeking independence from Damascus.

Syrian president Bashar Al Assad has tolerated Kurdish control over parts of the country but says he opposes the decentralised federal system they espouse and has described their ruling councils as "temporary structures".