By Kristina Wong - 09/29/14 09:37 PM EDT
Islamic State in Iraq and Syria militants are adjusting to U.S. airstrikes, making it more difficult to target them, an Air Force general said Monday.
ISIS fighters in Iraq and Syria had previously traveled in columns of vehicles with flags, Maj. Gen. Jeffrey Harrigian, Air Force assistant deputy chief of staff for operations, plans and requirements, told reporters at a briefing Monday.
Harrigian did not say how the Air Force would mitigate the difficulty, which points to some of the challenges the U.S. faces in conducting an air-only military campaign and not having capable forces on the ground yet.
Earlier Monday, the Pentagon admitted that some assessments of civilian casualties were "inconclusive" since the U.S. was only using drones to assess the results of strikes from the air.
"The evidence is going to be inconclusive often. Remember, we're using [intelligence, surveillance and reconnaissance] to determine the battle damage assessment," Pentagon spokesman Army Col. Steve Warren said Monday.
A defense official told The Hill earlier this month that accurate assessments of damage from strikes are impossible without U.S. forces on the ground to exploit the attack sites, since Iraqi and Syrian partners did not have the capability.
Harrigian said the Air Force has Joint Terminal Attack Controllers, who typically direct U.S. airstrikes from the ground, stationed at joint operations centers in Iraq to work with Iraqi and Kurdish forces out in the field to determine target locations.
However, Harrigian said that the air campaign has been decisive in critical areas: preventing ISIS from massing forces on a large scale and limiting its freedom of movement, disrupting the group's ability to communicate with each other and command forces in battle, and working to impact ISIS's financing.
He said, since Aug. 8, there have been more than 240 strikes in Iraq and Syria — the U.S. Air Force is responsible for 74 percent of strikes in Iraq and for 50 percent of airstrikes in Syria.
In addition the Air Force has flown 70 percent of the more than 3,800 sorties in Iraq and Syria, and 95 percent of the tanker sorties to refuel aircraft. There have also been more than 700 ISR sorties.
"The bottom line is, air power's targeted actions are disrupting ISIL's command and control, their logistics and infrastructure, and their freedom of movement," Harrigian said.