U.S. airstrikes killed three senior leaders of the Islamic State of Iraq and Syria in recent weeks, ABC News reported.

The American commander leading the U.S. effort in fighting against ISIS said the strikes were carried out to impact the extremist group's operations.

CBS News security correspondent David Martin confirmed the killings in recent weeks. Attacks were designed to undercut ISIS' ability to arm its fighters.

Army General Martin Dempsey, the chairman of the Joint Chiefs of Staff told the Wall Street Journal about the attacks on Thursday.

"It is disruptive to their planning and command and control," Gen. Dempsey said. "These are high-value targets, senior leadership."

Pentagon Press Secretary Rear Admiral John Kirby said, "I can confirm that since mid-November, targeted coalition airstrikes successfully killed multiple senior and mid-level leaders within the Islamic State of Iraq and the Levant, ISIL," using another name for ISIS.

Haji Mutazz, the man considered to be the right hand man to ISIS leader Abu Bakr al-Baghdadi was killed in the attacks.

The governor of ISIS, Radwin Talib and the terror group's head of military operations Abd al Basit were also killed in a series of attacks that occurred in November and December.

The U.S. and its coalition partners have conducted 1,361 airstrikes in Iraq and Syria so far, according to a Pentagon briefing made by the commander of the Combined Joint Task Force, Operation Inherent Resolve, Lieutenant General James Terry.

"Combined efforts like these are having a significant effect on Daesh's ability to command and control, to resupply, and to conduct maneuvering," Terry said.

He added that ISIS, "has been halted and transitioned to the defense and is attempting to hold what they currently have."

Terry also said that the coalition regained about 37 square miles of territory on Tuesday by conducting a total of 53 airstrikes that night.