The United States has placed the new ISIS leader on its blacklist of terrorists, naming him as Amir Mohammed Abdul Rahman al-Mawli.
Secretary of State Mike Pompeo said that al-Mawli was named the group’s leader after an October raid by US commandos killed its chief Abu Bakr al-Baghdadi.
The organization had earlier named Abu Ibrahim al-Hashimi al-Quraishi as its new head, but US officials acknowledged they knew little about him -- and later came to believe that ISIS was using his nom de guerre.
Al-Mawli "was previously active in al-Qaeda in Iraq and is known for torturing innocent Yazidi religious minorities," Pompeo said.
"We remain committed to ISIS's enduring defeat no matter who they designate as their leader," he said.
Al-Mawli was named a specially designated global terrorist, putting him on a list created after the September 11, 2001 attacks that makes any support to him a crime in the United States.
The State Department has already issued a $5 million bounty for information leading to al-Mawli's capture.
Al-Mawli rose through the ranks by issuing edicts to justify the persecution of the Yazidis, a campaign that the United Nations has described as genocide.
The militants killed thousands of Yazidis and abducted and enslaved thousands more women and girls as they rampaged across the Middle East.