The camps are spread throughout Islamic State-controlled areas of Iraq and Syria and are off limits in the U.S.-led international bombing campaign because of concerns about collateral damage, said officials familiar with planning and execution of the yearlong bombing campaign.

Additionally, the IS (also known as ISIS or ISIL) camps have been so successful that Islamic State leaders are considering expanding the camps to Libya and Yemen. Both states have become largely ungoverned areas in recent years.

The failure to target the training camps with U.S. and allied airstrikes is raising questions among some defense and intelligence officials about the commitment of President Obama and his senior aides to the current anti-IS strategy of degrading and ultimately destroying the terror group.

“If we know the location of these camps, and the president wants to destroy ISIS, why are the camps still functioning?” one official critical of the policy asked.