Earlier in the day, Yarallah said counterterrorism forces had "raised the Iraqi flag" in the central areas of The Citadel and al-Basateen.
Only a small area remains under ISIS control, in the north of the city, according to a map released by the Iraqi Joint Military Command.
Tal Afar is the last city still under the control of ISIS militants in Iraq's Nineveh province following the liberation of Mosul, about 45 miles to the east.
Col. Ryan Dillon, a spokesman for the US-led coalition against ISIS, told reporters on Thursday that ISIS fighters were "completely surrounded" in Tal Afar, with their resources drying up, as Iraqi forces moved closer to the city center.
Rasool, of the Iraqi Joint Military Command, said at the same news conference that 302 ISIS fighters had been killed since the start of the operation. He added that 33 rigged vehicles and 35 tunnels had been destroyed.
As the effort to retake Tal Afar got underway, the US-led coalition estimated that between 10,000 and 50,000 civilians remained in and around the city.
The United Nations warned of the risks to thousands of Iraqi families as they seek to flee the battleground in scorching heat.
UN refugee and migration agencies on Tuesday called for civilians to be given safe passage
out of the conflict zone.
"We fear that Iraqi civilians are likely to be held as human shields again and that attempts to flee could result in executions/shootings," said Andrej Mahecic, a spokesman for the UN refugee agency, UNHCR, in a news release.
He added that people in the area had reportedly been enduring very difficult conditions for months, with a lack of food, clean water and electricity.
Tal Afar was captured by the extremists on June 16, 2014, after a two-day battle.
ISIS fighters still control Hawija, west of Kirkuk, as well as the towns of Qaim, Rawa and Ana near the Syrian border.