The Syrian Islamic State leader Maher al-Agal was killed in an airstrike.
In a statement, the US Central Command (CENTCOMM) said al-Agal was killed in the drone strike in northwestern Syria.
A friend of his was also seriously injured in the explosion.
The statement added: “Extensive planning has gone into this operation to ensure its successful execution.
“An initial assessment indicates that there have been no civilian casualties.”
Al-Agal was the leader of the Islamic State in Syria and one of the top five ISIS leaders overall.
His death should be a major blow to ISIS’ efforts to reorganize itself as a guerrilla force after losing much of their territory.
The US military adds that he was responsible for “aggressively pursuing” the development of ISIS networks outside Iraq and Syria.
CENTCOMM spokesman Colonel Joe Buccino said: “This strike reaffirms CENTCOM’s steadfast commitment to the region and the enduring defeat of ISIS.
“The removal of these ISIS leaders will disrupt the terrorist organization’s ability to commit and carry out further attacks.
“ISIS continues to pose a threat to the US and partners in the region.
“CENTCOM maintains a sufficient and sustained presence in the region and will continue to combat threats to regional security.”
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