Khazir Front is under the control of the Kurdish Peshmerga forces but an agreement between Erbil, Baghdad and Washington allows Iraqi troops to pass through Kurdish territories on their way to Mosul.
Major routes leading to Mosul are controlled by Kurdish forces, and Iraqi troops hold positions south and southeast of the city.
The Peshmerga are also expected to play a part in the offensive against ISIS as a member of the joint Iraqi-Kurdish-coalition alliance.
