Islamic State (Isis) group's days in Mosul "are numbered" as Iraqi troops, backed by US-led coalition forces, continue to gain territory and consolidate their gains in their fight to liberate the second-largest Iraqi city, Pentagon spokesman Navy Capt Jeff Davis said in Washington on Monday (9 January).

He added that their IS (Daesh) fighters were seen deserting the battleground. The residents of the Isis stronghold were putting up a fierce resistance against the enemy, Davis told reporters during a media briefing on Operation Inherent Resolve – the offensive to liberate Mosul.

"[ISIL fighters] are surrounded on all sides by a superior force they're facing [in addition to] resistance from within the city, and they're being bombarded daily by coalition air and artillery strikes.

"And [ISIL] has no ability to reinforce or resupply. We do believe their days there, [particularly] in eastern Mosul, are numbered and they are beginning to realise it," Davis said.

He added that Isis fighters blew up the last of five bridges on Tigris River after Iraqi forces reached the vicinity of the southernmost bridge around Mosul. "All five bridges around Mosul are unusable," the defence department spokesman added.

"We are now seeing some makeshift attempts to [cross the river on foot] using planks," Davis said. He added that on another bridge, where the span over land was taken out by coalition forces, the jihadists were seen using a crane to move vehicles across the river, one by one in a very "painstaking way". The militants were also using slides to take cargo in boxes and slide them down onto the ground from the bridges that have coalition-damaged spans.

Davis said the morale among Isis fighters was going down every day. Besides, there were "fewer [vehicle-borne homemade bombs] than we had previously in Mosul, and indications are that ISIL can't respond to coordinated attacks on multiple axes".

"It's a sign of the fact that they recognise their defeat is imminent," Davis noted.

The US-led coalition was also giving air support to the anti-Isis offensive in Syria. Referring to the ongoing battle in Raqqa, which the Islamist militants claim as the capital of their so-called Caliphate, Davis said the Syrian Democratic Forces (SDF) had cleared most of the northern axis in the north and from the northwest, toward the southern segment of the city. He added that the SDF were within 4km of Raqqa and the Tabqu Dam on the Euphrates River.