IRBIL, Iraq — A top Iraqi commander told The Associated Press that the operation to retake the city of Mosul from the Islamic State group could be complete in three months or less.

"It's possible" that Mosul will be liberated in in that time frame, Lt. Gen. Talib Shaghati said in an interview with the AP on Tuesday evening. However, he warned it is difficult to give an accurate estimate of how long the operation will take because it is not a conventional fight.

"There are many variables," he said, describing the combat as "guerrilla warfare."

The massive offensive involving some 30,000 Iraqi forces was launched in October and Iraqi leaders originally pledged the city would be retaken before 2017. However as the fight enters its fourth month, only about a third of the city is under government control.

Iraqi forces — largely led by special forces — have slowly advanced across Mosul's east. Fierce IS counterattacks have killed and injured hundreds of Iraqi troops and inflicted considerable damage to Iraqi military equipment. Repeatedly, after what appeared to be swift progress on the ground, Iraqi forces have been pushed back by IS counterattacks overnight.

However, Shaghati said the counterattacks — specifically car bombings — have slowed. He estimated his forces are seeing less than half the number of IS car bomb attacks on the front than they were faced with when the operation first began.

The U.S.-led coalition bombed the bridges spanning the Tigris river connecting Mosul's east and west in November in an effort to stop the flow of car bombs to Iraqi frontline positions in the eastern half of the city.

Shaghati, the top commander of Iraq's special forces and the Commander of Iraq's Joint Military Operation said that while many forces are participating in the Mosul fight, Iraq's special forces are the only troops with the skills to fight IS.

"The forces who have the skills to fight guerrilla warfare is only the CTS," he said using an alternative acronym for Iraq's special forces who are also called the counter-terrorism forces. "They have flexibility and can act quickly," he said.

For the Mosul operation to continue, Shaghati said Iraqi forces need to continue to receive support and equipment from the U.S-led coalition. Since the Mosul operation began, the coalition says its planes have launched thousands of airstrikes in and around Iraq's second largest city.

Although Shaghati said he believes that the beginning of the Mosul operation marked the end of IS in Iraq, the country will likely struggle with terrorist threats long after IS is defeated in Mosul.

When asked if he expected levels of support to change when U.S. president-elect Donald Trump takes office this month, he said: "We believe that the support of our American friends is continuing and ongoing."