Taliban attacks in Kabul show they are losing on the battlefield, Afghan officials say.
The Iran-backed group's fighting alongside the Syrian regime has drawn terrorist groups and other actors to Lebanon.
Thousands of residents have been forced to flee their homes for fear of being used as human shields.
The new force, comprised of Iranian and foreign fighters, will fan sectarian tensions in the region and exacerbate rifts in Arab society, clerics say.
Insurgents besieged a college campus in Kabul, killing 13 and injuring 35.
Iran's support of the Taliban is meant to destabilise Afghanistan and undermine international efforts for peace.
Iran's involvement in the Syria war has prolonged the conflict and inflamed tensions throughout the region, experts say.
With ISIL leaders being killed one by one in Afghanistan, Abu Bakr al-Baghdadi's loyalists don't have a chance of survival, observers say.
Air and ground assaults by Afghan troops and planes have blasted ISIL out of its foothold.
Afghanistan is going after drug use and traffickers to dry up terror financing.