Air Force Colonel John Dorrian conducted a press briefing at the Pentagon on Wednesday, in which he indicated that the progress made by coalition forces and the Iraqi military in recent days will have reverberating effects throughout the ISIS command structure, and will eventually lead to their defeat.

The ISIS-controlled area is “shrinking steadily with each passing day,” Colonel Dorrian told reporters. “The main effort is to isolate the remaining enemy remnants in the west part of Mosul,” he added, noting the terrorists will “either surrender or they’re going to be killed there.”

On Thursday, Iraqi forces continued to push through Mosul, capturing the airport, an important strategic launching point for further efforts to wipe the terrorist presence from Iraq.

“We are attacking Daesh (Islamic State) from multiple fronts to distract them and prevent them regrouping,” said federal police captain Amir Abdul Kareem, whose units are fighting near the Ghozlani military base in Mosul. “It’s the best way to knock them down quickly.”

Coalition air strikes destroyed 23 ISIS mortar and artillery installations over the past week, according to a Pentagon news release, which they indicated would make the capture of the airport possible prior to Thursday’s advance.

“Conditions have been set for ISIS’s defeat through their significant effort to reduce their command and control, their weapons and their financial resources,” Dorrian said, but it isn’t all good news.  Although he commended the Iraqi forces for their effort in purging the city of ISIS strongholds, a potentially bigger challenge lies ahead, as more than a hundred thousand buildings will need to be searched and cleared of ISIS combatants once the city is firmly under Iraqi control.

The oldest portions of Mosul contain extremely narrow roads, which will make it difficult to maneuverer Iraqi military vehicles, but Dorrian suggested that a potential bright side to that difficulty could be that vehicle-born explosives used by ISIS would also be limited.

“We do expect it to be an extraordinarily difficult fight,” Dorrian said of the future endeavor to clear out remaining pockets of terrorists in the city.  Further exacerbating the issue is a network of passageways and tunnels ISIS has built throughout the city to allow them to hide and fight among civilians, and then evade capture by disappearing once again into the tunnels.