U.S.-backed Syrian militias seized the town of Tabqa and Syria's largest dam from the Islamic State extremist group on May 10, clearing the way for an assault on Raqqa.
The fall of Tabqa, some 40 kilometers west of Raqqa, leaves no other major urban settlements on the road to the militant group's self-proclaimed capital and base of operations in Syria.
The Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab fighters, have been battling IS for control of Tabqa for weeks and recently have received heavier weaponry from the United States to bolster their campaign in a move that alienated NATO ally Turkey.
Besides the upgrade in weapons, the Syrian forces received help in capturing the strategically important town and its adjacent dam from the U.S.-led international coalition fighting IS, which has provided backup with air strikes and special forces.
Nasser Haj Mansour, an adviser to the SDF, said the town and the adjacent Tabqa dam are now "completely liberated" after the SDF drove all the IS militants out.
Brett McGurk, a U.S. special presidential envoy for countering IS, confirmed on Twitter that Tabqa had been retaken.