Abu Bakr al-Turkmani died September 10 in a strike in Tal Afar in northern Iraq, Pentagon press secretary Peter Cook told reporters.
"He was an ISIL administrative emir, he was part of Al-Qaeda in Iraq before joining ISIL and was a close associate to multiple ISIL senior leaders in Iraq," Cook said, using an alternative acronym for the Islamic State group.
Cook also confirmed the death of French jihadist David Drugeon, who died in an airstrike near Aleppo, Syria on July 5.
"As an explosives expert, he trained other extremists in Syria and sought to plan other attacks against Western targets," he added.
AFP reported Drugeon's death on September 11.
He was born in 1989 and had converted to Islam aged 13 before drawing close to ultraconservative Salafist Muslims.