British Defense Secretary Michael Fallon says Western-backed Syrian forces should be able to isolate the Islamic State (IS) militant group's self-declared capital in Syria by this spring, setting up an attack on the city itself.
"I hope that isolation will be completed by the spring and then operations to liberate Raqqa itself can begin thereafter," Fallon said on February 11 during a visit to Irbil, the capital of the Kurdish autonomous region in northern Iraq.
The campaign against Raqqa by the Syrian Democratic Forces -- which include the Syrian Kurdish YPG militia -- was launched in November.
IS has been losing ground in neighboring Iraq and is putting up fierce resistance as it fights to preserve its foothold in Syria.
The top U.S. Army commander in Iraq, Lieutenant General Stephen Townsend, said on February 8 that Western-backed forces would recapture two remaining IS strongholds -- Raqqa in Syria and Mosul in Iraq -- within six months.
Iraqi and Kurdish forces last month pushed IS militants out of the eastern side of Mosul and are preparing an offensive on the western section of the city.
Islamic State declared a so-called caliphate in parts of Syria and Iraq in 2014.
The militants eventually controlled around one-third of Iraq, but Iraqi forces and their allies have taken back about two-thirds of that territory.