Islamic State's self-proclaimed capital, the Syrian city of Raqa, will soon be isolated from the rest of the world, a spokesman for the US-led coalition fighting the jihadist group.

Although it will not be completely encircled, "it will be very difficult to get into or out of the city," Colonel John Dorrian said in a video conference from Baghdad."

"What we would expect is that within the next few weeks the city will be nearly completely isolated," Dorrian said.

The coalition has been gradually tightening a vice on IS in Iraq and Syria.

US-backed Iraqi forces have recovered part of the Iraqi city of Mosul, although the city's western districts have yet to be retaken.

Raqa is the coalition's next big objective. Arab-Kurdish forces backed by the coalition have launched an offensive on Raqa, advancing on the city from the north.

But the issue of who exactly will assault the predominantly Arab city has not yet been worked out.

Turkey has expressed interest in taking part in the operation, with Turkish Foreign Minister Mevlut Cavusoglu indicating that his country is ready to deploy special forces to take part in the battle.

Turkey opposes giving added weight to the Syrian Democratic Forces, as the Arab-Kurdish coalition is called, regarding it as little more than a front for the Kurdish YPG militant group, which Ankara considers a terror organization.

"We have said for many months the US would be opened to a Turkish role," Dorrian said.

Turkey already has troops in northern Syria, having launched an offensive in the area in August against IS and Kurdish militants.

After a rapid advance, the Turkish army, which was acting in support of Syrian rebel groups, has been embroiled in recent weeks in deadly combat around Al-Bab, in northern Syria.

Death toll in strikes on Syria ex-Qaeda hits 46: monitor
Beirut (AFP) Feb 8, 2017 - The death toll in air strikes against Al-Qaeda's former affiliate in Syria in the northwest of the country has risen to 46, including 24 civilians, a monitor said on Wednesday.

The dead included 10 children and 11 women, the Syrian Observatory for Human Rights said, adding that the toll could rise further because of the number of wounded with serious injuries.

The raids hit the headquarters of former Al-Qaeda affiliate Fateh al-Sham in Idlib and several adjacent neighbourhoods of the city at dawn on Tuesday.

Observatory head Rami Abdel Rahman said he could not determine whether the raids were carried out by Syrian government ally Russia or a US-led coalition battling jihadists.

But Moscow quickly denied on Tuesday that its planes had struck the city.

In recent weeks, Fateh al-Sham has come under increasing in Idlib, the last province in Syria almost entirely in rebel hands.

Bombing raids against the group have escalated, including one US strike on a training camp in January that killed more than 100 fighters.

Rebel groups have held Idlib province since the spring of 2015, four years after the Syrian conflict broke out.

More than 310,000 people have died since the war began and millions have been forced to flee their homes.