The leader of the Islamic State (ISIS) terror group in Afghanistan and Pakistan was killed by a U.S. drone last month, a U.S. defense official confirmed to Fox News Friday.

The operation agaisnt Hafiz Saeed Khan was first disclosed by Afghanistan’s ambassador to Pakistan.

Omar Zakhilwal told Reuters: “I can confirm that ISIS Khorasan leader Hafiz Saeed Khan, along with his senior commanders and fighters died in a U.S. drone strike on July 26 in Kot district of Afghanistan’s Nangharhar province.”

Khan, a former member of the Pakistani branch of the Taliban, had sworn allegiance to Middle East-based ISIS. He was earlier reported killed last year but the death was never confirmed.

Khan’s death is a blow to efforts by ISIS to expand its territory and its jihadist push into Afghanistan and Pakistan.

U.S. and Afghan leaders have been concerned about the growth of IS in Afghanistan. They were targeted by a U.S.-backed Afghan military offensive last month, in which five U.S. commandos were injured.

Khan is the second prominent jihadist to be killed in the region in three months. Afghan Taliban leader Mullah Akhtar Mansour was killed by a US airstrike strike in Pakistan in May.

(AP)