US-Led Coalition Says Mosul Op Could Take Weeks or More

The operation Iraqi forces launched on Monday to retake the city of Mosul from the Islamic State group could last weeks and "possibly longer", a top US general said.

Lieutenant General Stephen Townsend, commander of the US-led coalition battling the jihadist group, warned that victory in IS's last major stronghold in Iraq could take time.

"This operation to regain control of Iraq's second-largest city will likely continue for weeks, possibly longer," he said in a statement.

Iraqi Prime Minister Haider al-Abadi announced earlier Monday that the long-awaited operation to recapture Mosul was under way.

"This may prove to be a long and tough battle, but the Iraqis have prepared for it and we will stand by them," Townsend said.

Following the fall of Mosul to IS more than two years ago, the United States led what has now become a more than 60-nation coalition supporting the anti-IS effort in Iraq and Syria.

Most of the coalition's support has come in the shape of air strikes and training but US, French and British special forces are now also on the ground to advise local forces in battle.

Townsend said the coalition had trained and equipped more than 54,000 Iraqi forces.