The U.S.-led coalition fighting the Islamic State (IS) extremist group in Iraq said it has doubled to about 450 the number of military advisers assisting Iraqi troops engaged in the campaign to retake Mosul.
"We have increased the number of advise and assist forces that are there with the [Iraqi Security Forces]," coalition spokesman Colonel John Dorrian said in a video conference from Baghdad on January 4.
Dorrian said the reinforcements were part of a series of measures taken to "accelerate the advance of the Iraqi security forces."
While military advisers work behind the front lines, they have already entered the city several times, he said.
American military forces are carrying out air and artillery strikes in Iraq as part of the U.S.-led coalition, and U.S. special forces have also fought IS on the ground.
There are about 5,000 American military personnel in Iraq, according to the coalition.
Even with more advisers, officials say it could be months before Iraqi forces are able to completely retake Iraq's second largest city, where hundreds of thousands of civilians still live.
"There are more than 200,000 buildings in Mosul and...you end up having to clear each one," Dorrian said.