U.S.-backed Iraqi army units on Wednesday took control of the last major road out of western Mosul that had been in Islamic State's hands, trapping the militants in a shrinking area within the city, a general and residents said.
The army's 9th Armored Division was within a kilometer of Mosul's Syria Gate, the city's northwestern entrance, a general from the unit told Reuters by telephone.
"We effectively control the road, it is in our sight," he said.
Mosul residents said they had not been able to travel on the highway that starts at the Syria Gate since Tuesday. The road links Mosul to Tal Afar, another Islamic State stronghold 60 km (40 miles) to the west, and then to Syria.
Iraqi forces captured the eastern side of Mosul in January after 100 days of fighting and launched their attack on the districts that lie west of the Tigris river on Feb. 19.
If they defeat Islamic State in Mosul, that would crush the Iraq wing of the caliphate declared by the group's leader Abu Bakr al-Baghdadi in 2014 from the city's grand old Nuri Mosque.