An American airstrike has targeted and likely killed a top Islamic State leader in Libya, in a strike that happened just as the Paris terrorist attacks were underway, the Pentagon said Saturday.

Pentagon press secretary Peter Cook said the U.S. strike targeted Abu Nabil, also known as Wissam Najm Abd Zayd al Zubaydi, an Iraqi national who was a longtime al-Qaida operative and the senior Islamic State leader in Libya. This was the first airstrike against an Islamic State leader in Libya and comes on the heels of a U.S. and British operation late last week in Syria that officials believe likely killed Islamic State militant Mohammed Emwazi. Emwazi was a Kuwaiti-born British citizen known as "Jihadi John," who appeared in several videos depicting the beheadings of U.S. and Western hostages.

A senior U.S. official said that the latest airstrike in Libya struck a command and control center near the eastern port city of Darnah and likely killed Nabil and others with him. Officials are still assessing the results of the strike but called Nabil's death strongly probable.

The official says the strike by an F-15 fighter jet took place shortly after the Paris terrorist attacks were underway, but had been planned for some time. The aircraft were in the air when the attacks began in France.

The official was not authorized to discuss the strike publicly so spoke anonymously.

Cook said that Nabil also may have been the spokesman in the video of the February 2015 mass killings of Coptic Christians in Libya, also likely by Islamic State militants. He said that Nabil's death "will degrade ISIS' ability to meet the group's objectives in Libya, including recruiting new ISIS members, establishing bases in Libya, and planning external attacks on the United States." Cook used an alternative acronym for the militants.