A US airstrike in northern Iraq has killed an Islamic State operative who was a person of interest in the attack in the attack on the US embassy in Benghazi, Libya, in 2012, the Pentagon said Monday.

Pentagon spokesman Colonel Steve Warren said Tariq bin al-Tahar bin al-Falih al-'Awni al-Harzi of Tunisia was killed in Mosul on June 15, saying "his death degrades ISIL's ability to integrate North African jihadists into the Syrian and Iraqi fight and removes a jihadist with long ties to international terrorism."