Hafiz Saeed Khan (center in photo) was killed in a US drone strike on July 26 near the Afghanistan-Pakistan border, US and Afghan officials confirmed Friday.

Khan was responsible for the so-called Khorasan province of the "Islamic State" (IS), which includes Pakistan, Afghanistan and parts of neighboring countries.

The death of the regional chief is a major blow to the militant group, which has sought to expand its sway from the Middle East to Afghanistan and Pakistan.

Afghan intelligence falsely claimed last year that Khan had been killed, but that report was never confirmed.

But, on Friday, Omar Zakhilwal, Afghanistan's ambassador to Pakistan, confirmed the death.

"I can confirm that ISIS Khorasan leader Hafiz Saeed Khan along with his senior commanders and fighters died in a US drone strike on July 26 in Kot district of Afghanistan's Nangharhar province," he told Reuters, using an acronym for IS.

A US defense official also confirmed Khan's death, saying the airstrike took place during joint operations by US and Afghan special operations forces against IS in the southern part of Nangarhar province.

The blow comes less than six months after the outfit's No. 2, Abdul Rauf Khadim, was killed in a strike. In May, a US drone killed Afghan Taliban leader Mullah Akhtar Mansour.

The Taliban and IS are rivals and often clash. Last year, a group of Taliban split off to join IS as it set up in the region.

US and NATO maintain largely noncombat forces that support and train Afghan security forces. However, Afghan forces still rely on US airpower in operations against the Taliban and IS.

cw/cmk (AFP, Reuters)