Libya's senior "Islamic State" (IS) leader Abu Nabil - an Iraqi national and an al-Qaeda operative - has reportedly died during a targeted airstrike, the Pentagon announced on Saturday.

The airstrike, which occurred on Friday, was "authorized and initiated prior to the terrorist attack in Paris" according to officials.

"Nabil's death will degrade ISIL's ability to meet the group's objectives in Libya, including recruiting new ISIL members, establishing bases in Libya, and planning external attacks on the United States," said Pentagon press spokesman Peter Cook in a statement, using an another name for IS.

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

An F-15 fighter jet hit a command and control center near the eastern port city of Darnah, a senior US official told the Associated Press under condition of anonymity. The Pentagon is still analyzing the strike results, but said Nabil's death was highly probable.

Cook added that Nabil - also known as Wissam Najm Abd Zayd al Zubaydi - was most likely the spokesman in a February 2015 video which showed the execution of 21 Egyptian Christian migrant workers. The video released by IS showed the beheading of hostages wearing orange jumpsuits along a coastal region in the Libyan province of Tripoli.

Since a 2011 revolt which toppled Libyan dictator Moammar Gadhafi, the country has been mired in a civil conflict, allowing IS to gain ground. The extremist group, mainly based in Syria and Iraq, now holds territory around the Libyan city of Sirte and other areas on the southern shore of the Mediterranean.

The announcement on Saturday came just two days after the alleged death of the IS executioner known as "Jihadi John." A joint US-British operation late last week targeted the militant who appeared in numerous videos which depicted the beheadings of Western hostages. The US has said it is "reasonably certain" that he was killed during a drone strike in Syria.

rs/cmk (AP, AFP, dpa)