US President Barack Obama said he expects Iraq’s second city Mosul to be retaken from the by the Takfiri group, ISIL, "eventually" by the end of the year.

US President Barack Obama said he expects Iraq's second city Mosul to be retaken from the by the Takfiri group, ISIL, "eventually" by the end of the year.

"As we see the Iraqis willing to fight and gaining ground, let's make sure that we're providing them more support," Obama said in an interview with CBS News on Monday.

"We're not doing the fighting ourselves, but when we provide training, when we provide special forces who are backing them up, when we are gaining intelligence -- working with the coalitions that we have -- what we've seen is that we can continually tighten the noose," he added.

"My expectation is that by the end of the year, we will have created the conditions whereby Mosul will eventually fall."

Mosul, in northern Iraq, was overrun during a Takfiri offensive in June 2014 and has become an ISIL stronghold.

Washington heads an international coalition that is allegedly carrying out strikes against ISIL and also providing training and other assistance to forces fighting the insurgents in both Iraq and neighboring Syria.

Obama's comments came on the same day that Defense Secretary Ashton Carter said Washington would send Apache attack helicopters and more troops to Iraq.

Carter, on an unannounced trip to Baghdad, said the Apaches being sent to Iraq will support Iraqi efforts to surround and eventually recapture Mosul.

Iraqi forces have begun preparatory operations in Nineveh province, of which Mosul is the capital.