Leaders of Syria’s moderate opposition are warning that American airstrikes alone will not defeat the Islamic militants that have taken over parts of their country.

Free Syrian Army (FSA) officials told The Daily Beast that airstrikes could exacerbate the threat from the Islamic State in Iraq and Syria (ISIS) unless there’s a coordinated plan to destroy the group. 

“Airstrikes against ISIS inside Syria will not be helpful. Airstrikes will not get rid of ISIS. Airstrikes are like just tickling ISIS,” said Hussam al Marie, the spokesman for the FSA in northern Syria.

President Obama is reportedly weighing possible airstrikes on ISIS in Syria, which would expand upon the airstrikes already carried out against the group in Iraq.

{mosads}Al Marie said ISIS is not a state that can easily be targeted since its members are spread out in Syria. Militants also use civilian buildings in Syria’s cities, he added. 

“So airstrikes will not be enough to get rid of these terrorists and at the same time, they might hit civilians. That’s the problem,” he said.

ISIS also has “sophisticated weapons” now, which al Marie said they stole from Americans.

Two FSA officials told The Daily Beast the West has been calling on its forces in the last week to fight ISIS after the group released a video showing the beheading of U.S. journalist James Foley.

“Since a week ago, now we are getting a lot of communication from Western powers saying, ‘What can we do to help you against ISIS?’ They ask us go to fight ISIS and say ‘We will support you,’” Iyad Shamsi, commander of FSA’s Eastern Front, told The Daily Beast. 

He also said Foley’s death demonstrates the Obama administration’s failure to confront ISIS’s rise.

“The ISIS killing of James Foley and the threatening of the other American journalists reflects that America didn’t pay much attention to the threat and growth of ISIS inside Syria,” Shamsi said. “We were very clear that we wanted to cooperate with the Americans. They didn’t listen. They paid a price.”