The US-backed Syrian Democratic Forces (SDF) will soon launch an offensive to oust ISIS from Deir al-Zor province, an official from the alliance said Friday, as the terrorist group successfully pushed back regime forces advancing on one of the last towns still in the organizaton’s hands in Raqqa province. Ahmed Abu Khawla, head of the Deir al-Zor military council which fights under the SDF, told Reuters that the assault might begin "within several weeks" in parallel with the battle for Raqqa city. The SDF alliance of Kurdish and Arab fighters has been battling inside the historic Old City of Raqqa, ISIS’ de facto capital in Syria. Spearheaded by the Kurdish YPG militia, the SDF began its assault in June, after months of fighting to encircle Raqqa with air strikes and special forces from the US-led coalition. As ISIS has come under pressure in Raqqa, many of its forces have fallen back on the towns and cities further east along the Euphrates in Deir al-Zor province. "The operation to liberate Deir al-Zor will begin very, very soon," Khawla said, adding that his unit had already "entered Deir al-Zor territory and liberated several towns" there. Col. Ryan Dillon, a spokesman for the US-led coalition, said its focus remained on Raqqa. Meanwhile, the Britain-based Syrian Observatory for Human Rights said ISIS militants killed a number of regime troops and seized their vehicles as they advanced on the town of Maadan. The Observatory said at least 34 Syrian soldiers and 12 militants were killed. Maadan lies along the southern banks of the Euphrates River and is 60 kilometers east of the city of Raqqa. Syrian forces are advancing along the south and west bank of the Euphrates towards where the city of Deir al-Zor is located, while the SDF is mostly on the north and east bank, where Raqqa is located.