Story highlights Operation was planned and put in motion before Paris terror attacks

Pentagon: This is the first U.S. strike against an ISIS leader in Libya

Washington (CNN) The U.S. military on Friday killed the senior ISIS leader in Libya, the Pentagon said.

Abu Nabil, an Iraqi national and longtime al Qaeda operative, was taken out in an airstrike authorized and initiated prior to the terrorist attacks in Paris on Friday night, said Pentagon Press Secretary Peter Cook.

"While not the first U.S. strike against terrorists in Libya, this is the first U.S. strike against an ISIL leader in Libya and it demonstrates we will go after ISIL leaders wherever they operate," Cook said.

Nabil -- also known as Wissam Najm Abd Zayd al Zubaydi -- may also have been the terror group spokesman who appeared in a February video showing the execution on a beach by ISIS of Coptic Christians who had been taken prisoner.

Cook said Nabil's death will degrade ISIS's ability to recruit new members in Libya, establish bases in the country, and plan external attacks on the United States.