The US says it believes the leader of Islamic State in Afghanistan and Pakistan has been killed in a airstrike.

The death of Hafiz Saeed Khan in eastern Afghanistan was initially revealed by the country's ambassador to Pakistan.

The US department of defence has since confirmed that it believes the militant leader was killed in an airstrike on July 26th.

In a statement, deputy press secretary Gordon Trowbridge said: "Khan was known to directly participate in attacks against U.S. and coalition forces, and the actions of his network terrorized Afghans, especially in Nangarhar [province].

"Nangarhar province has been a hotbed for ISIL-Khorasan activity since the summer of 2015.

"ISIL-K uses the area to train, equip, disseminate and control fighter pipelines, providing ISIL-K commanders throughout Afghanistan with a continuous supply of enemy fighters from this province," he added.

Mr Trowbridge says Khan's death will 'disrupt' IS operations in Afghanistan.

The US says it carried out operations against IS in the region throughout the month of July.

The statement does not confirm reports that the airstrike was carried out by a drone.

Khan was a former member of the Pakistani branch of the Taliban, but had sworn allegiance to the so-called Islamic State.

He was earlier reported killed last year but the death was never confirmed.