Iraqi security forces are only days away from completing the operation to recapture Mosul from ISIS, the BBC quoted army's chief of staff as saying on Friday.
Lt Gen Othman al-Ghanimi said he hoped the group would be defeated in the city before the Islamic holy month of Ramadan begins on 26 May.
Recent gains in the north meant the remaining militants were being squeezed into an ever smaller area, he added.
Mosul fell to ISIS in 2014 and is its last major urban stronghold in Iraq.
Pro-government forces launched a major offensive to retake the city in October with the support of US-led coalition air strikes.
They managed to take full control of the eastern half of Mosul in January and started an assault on the west the following month.
Fewer than 1,000 militants are now besieged in several north-western districts, including the Old City, along with as many as 450,000 civilians.
"The security forces are carrying out a big and effective effort. I say that ISIS will be finished in days, God willing," Gen Ghanimi said.
"I say that the rest of Mosul will be liberated before the holy month of Ramadan."