US-backed Iraqi security forces closing in on the ISIL-held western half of Mosul have stormed the city's airport and a nearby military base, state television said.

Counterterrorism service (CTS) troops and elite interior ministry units known as Rapid Response forces descended on the airport early on Thursday and the nearby Ghazlani military complex, CTS spokesman Sabah al-Numan told state TV.

"This is one of the major achievements that the Iraqi forces were hoping to get in the first phase of going towards the Western side of the city," said Al Jazeera's Osama Bin Javaid, reporting from Erbil.

"This area is about 30 kms away from the western edge of the city, and Iraqi forces now say that they are in full control.

"They say that the two main buildings of the city have been destroyed by ISIL and they have found a number of car bombs parked on strategic locations in the entry points and along the runway of Mosul International Airport."

The airport and military complex, which includes barracks and training grounds and sprawls across an area close to the Baghdad-Mosul highway was captured by ISIL fighters when they overran Mosul in June 2014.

The advances come days after Iraqi forces officially launched the operation to push ISIL out of Mosul's western half.

The operation to retake Iraq's second largest city was officially launched in October and in January its eastern half was declared "fully liberated."

A US-led coalition has been providing close air support throughout the campaign to retake Iraq's second-largest city.

US special operations forces are embedded with some Iraqi units and thousands of US troops are in Iraq providing logistical and other support.

US Secretary of Defence Jim Mattis was holding discussions with US and Iraqi officials, a week before he is expected to present a new strategy to President Donald Trump for defeating ISIL .

Trump has repeatedly vowed to eliminate the group but has provided few details about how his approach might differ from that of the Obama administration, which had partnered with Syrian and Iraqi forces to drive ISIL out of several towns and cities.

The battle for western Mosul , the group's last major urban bastion in Iraq, is expected to be the most daunting yet.

The streets are older and narrower in that sector of the city, which stretches west from the River Tigris, forcing Iraqi soldiers to leave the relative safety of their armoured vehicles.

WATCH: Will latest Iraqi offensive mean end of ISIL in Mosul?

The presence of up to 750,000 civilians also poses a challenge .

Two suicide car bombers struck army and paramilitary forces west of Mosul on Monday, killing and wounding a number of troops, two army officers said, without specifying the number of casualties.

A third suicide car bomber was blown up before reaching the troops, they said, speaking on condition of anonymity because they were not authorised to brief the media.

ISIL claimed responsibility for two attacks in an online statement, saying the attackers were British and Iraqi.



