Afghan President Ashraf Ghani has vowed to "bury" the affiliate of the so-called ’Islamic State of Iraq and the Levant’ (ISIL) takfiri group’s in Afghanistan.

Afghan President Ashraf Ghani has vowed to "bury" the affiliate of the so-called 'Islamic State of Iraq and the Levant' (ISIL) takfiri group's in Afghanistan, after Washington granted the US military the legal authority to strike the militants in the country, Kabul media outlets reported Monday.

The group, which controls territory across Syria and Iraq, has made alarming inroads in Afghanistan's eastern Nangarhar province, as the country grapples with a resurgent Taliban insurgency.

ISIL terrorists claimed responsibility for a deadly gun and bomb siege targeting the Pakistani consulate in eastern Jalalabad city on January 13, the group's first major attack in an Afghan city.

In recent months Afghan forces backed by US drones launched a scorched earth offensive to beat back ISIL in Nangarhar, where the group's rein of terror has displaced thousands of people.

"This could be a point of no return for Daesh -- we will bury Daesh," Ghani told BBC in an interview released Monday, using the Arabic acronym for ISIL.

"Afghans are now motivated by revenge. They (ISIL) have confronted the wrong people," Ghani said on the sidelines of World Economic Forum in the Swiss resort of Davos.

The US State Department earlier this month formally designated the group's affiliate in Afghanistan and Pakistan - which calls itself "Khorasan Province" - as a terrorist organization.