Raqqa: Battle to oust Isis from second capital city could begin 'within weeks', says US defence chief

Experts believe the operation to force Isis from Mosul could take months

Isis troops near Raqqa, Syria

The US-backed operation to oust Isis from the Syrian city of Raqqa could begin “within weeks”, America’s defence chief has claimed.

As a coalition of forces advance on Mosul in Iraq, Ash Carter has said that the groundwork is being readied to switch their aim to Raqqa, the second of Isis’s de facto capital cities.

Speaking to NBC in Paris, the US Defence Secretary suggested the second operation was imminent.

Ash Carter said the special operations force will launch clandestine missions in Iraq and Syria (AP)

“It starts in the next few weeks,” he said. “That has long been our plan and we will be capable of resourcing both.”

He added: “It’s been long a part of our plan that the Mosul operation would kick off when it did. This was a plan that goes back many months now and that Raqqa would follow soon behind.”

Mosul and Raqqa are the two main strongholds of the Islamic State group, acting as the capitals of their so-called caliphate and providing a source of revenue and territory. The Iraqi military, supported by US and coalition air power and military advisers, began the push to retake Mosul on October 16. The Associated Press said the battle for the city, which has a large civilian population, is expected to take months and follows successful campaigns this year to retake the main cities in Iraq’s western Anbar province.

At a press conference with French Defence Minister Jean-Yves Le Drian after a meeting with 11 other defence chiefs, Mr Carter said there has been no delay in the intended start of the Raqqa operation, and that there will be “overlap” with the Mosul fight.

“The collapse and destruction of [Isis] in Iraq and Syria will destroy both the fact and the idea that there can be a caliphate based upon this ideology,” he said. “However, there will continue to be, and there are now, those there or elsewhere who aspire to either coordinate or inspire attacks on our homeland.”

Yet not others have warned that the US and other nations should not underestimate the challenge confronting the forces trying to dislodge Isis from Mosul and Raqqa.

One senior military official told the AP that conducting major operations in the two cities Raqqa and Mosul at the same time would stretch the coalition. He says the Raqqa campaign should wait until the Iraqis have made more significant progress in Mosul, where resistance from the militants has been described as heavy.

The senior military official said that if the Mosul and Raqqa operations were launched simultaneously, the biggest strains would be on fighter jets and reconnaissance aircraft. The coalition should be able to start the Raqqa operation in the near future, the official said, but declined to give a more precise timeline.

When asked whether US special forces or other troops would be sent inside Mosul or Raqqa to gather intelligence or hunt “high-value combatants,” Mr Carter replied: “They are not near [Mosul] at this time ... Our forces do accompany .... the Iraqi security forces and the Peshmerga. So they will get nearer to the city as those forces get nearer to the city…We are not going to be part of the occupation or hold forces.”

Iraqi security forces and the Kurdish militia have faced Isis suicide attacks, car bombs and other attacks in their march toward Iraq's second-largest city which the extremists captured in 2014.

Isis is expected to give ground gradually on the outskirts of Mosul but then stiffen their resistance as the fighting moves closer to the center of the city.