BEIRUT (Reuters) – A U.S.-backed campaign against Islamic State in eastern Syria will accelerate now the jihadist group has been defeated in its former capital Raqqa, a spokesman for U.S.-allied Syrian militias said on Wednesday.

The Syrian Democratic Forces (SDF), which announced the defeat at Raqqa on Tuesday, will redeploy fighters from the city to frontlines with Islamic State in the eastern province of Deir al-Zor, Talal Silo told Reuters by telephone.

The SDF is fighting Islamic State in Deir al-Zor in areas to the east of the Euphrates River. The Syrian government, supported by the Russian air force and Iran-backed militias, is waging a separate campaign against the jihadists in the province, focused mostly in areas to the west of the river.

Islamic State has lost ground rapidly there in recent weeks. The Syrian army and its allies are battling for control of the last remaining IS-held areas of Deir al-Zor city, and have also captured the town of al-Mayadin from IS.

Silo said the Raqqa victory would have a “positive impact” on the SDF’s campaign in Deir al-Zor because it meant fighters could be redeployed as internal security forces take control of Raqqa.

“Most of the military forces will head towards these areas to continue the participation in the campaign with the Deir al-Zor Military Council,” he said. The Council is a militia leading the SDF’s campaign in the province.

“This is all to the benefit of the campaign and accelerating the end of this campaign,” he said.

(Reporting by Tom Perry; editing by John Stonestreet)