Lieutenant Colonel Salam al-Obeidi was speaking to AFP inside the devastated Old City, about 50 metres from what is left of the "Hadba" leaning minaret the jihadists blew up four days earlier.
"Sixty-five to 70 per cent of the Old City has been liberated, there is less than a square kilometre left to retake," said Obeidi, from the elite Counter-Terrorism Service that has spearheaded the assault.
He estimated that only "a few hundred Daesh fighters" were left in the Old City, using an Arabic acronym for IS.
The cylindrical shaft of the minaret came tumbling down when IS on June 21 detonated explosives the jihadists had rigged to it.
More From This Section
The jihadists simultaneously blew up the nearby Nuri mosque, where Abu Bakr al-Baghdadi gave his first sermon as IS leader in July 2014, his last public appearance to date.
The narrow, windy streets of the Old City, an area packed with heritage treasures covering about three square kilometres on Mosul's west bank of the Tigris, were littered with rubble.
The jihadists, who have no escape from their last redoubt in the Old City, have mounted a fierce defence using booby traps, mortars, suicide attacks and snipers.
The massively outnumbered and outgunned group of die-hard jihadists are holding tens of thousands of civilians as human shields.