A US-backed Syrian alliance, which dealt a major setback to Islamic State this week, announced on Sunday the formation of a military council to capture a strategic northern town from the extremist militia.
The Democratic Forces of Syria (DFS), an alliance of Kurds and Arabs, said that the council comprising affiliated factions had been set up to "liberate" the town of al-Bab from the control of Islamic State.
Al-Bab is located west of the town of Minbij. The DFS announced on Friday Minbij's "liberation" from Islamic State after a campaign backed by US-led airstrikes that started in late May.
The factions forming the al-Bab military council called on locals to join their forces in fighting Islamic State.
"We also call on the US-led international alliance to support us in our struggle," they added in a joint statement.
"Our council will work to confront Daesh terrorists, being the people's enemy," the council's chief Jamal Moussa, using an Arabic acronym for Islamic State, said at a press conference in a village near al-Bab.
Capturing al-Bab would completely cut Islamic State's links with the Turkish border, as well as linking up the main Kurdish-held territory in northern Syria with the enclave of Efrin in the north-west.
But any such move would also be likely to inflame relations between the DFS, rival Syrian opposition forces and Turkey, which is wary of the Kurds' links with the banned Kurdistan Workers' Party inside its territory.