Iraqi forces on Wednesday retook the control of the last major road out of western Mosul that had been in Daesh’s hands, trapping the militants in a shrinking area within the city, Reuters quoted an Iraqi general and residents.

The Iraqi general said the army's 9th Armored Division was within a kilometer of Mosul's Syria Gate, the city's northwestern entrance, the report added.

"We effectively control the road, it is in our sight," he said.

In the meantime, the 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 Daesh stronghold 60 km 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 Daesh 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.

The U.S-led coalition effort against Daesh is killing the group's fighters more quickly than it can replace them, British Major General Rupert Jones, deputy commander for the Combined Joint Task Force said.

With more than 45,000 killed by coalition air strikes up to August last year, "their destruction just becomes really a matter of time," he said on Tuesday in London.

Several thousand militants, including many who traveled from Western countries to join up, are believed to be in Mosul among a remaining civilian population estimated at the start of the offensive at 750,000, the report said.