Iraqi troops on August 22 recaptured from the Islamic State extremist group the first three districts of the city of Tal Afar, as U.S. Defense Secretary Jim Mattis visited Baghdad in a show of support.
The United Nations said thousands of civilians had fled Tal Afar in the two days since the start of the broad offensive backed by the U.S.-led coalition fighting IS.
After meeting Iraqi Prime Minister Haidar al-Abadi in Baghdad, Mattis said IS militants were "on the run."
"Cities have been liberated, people freed from ISIS, from Daesh," Mattis said, using alternative names for IS.
The militants had not been able "to stand up to our team in combat, and they have not retaken one inch of ground that they lost," he said.
Iraqi troops backed by a U.S.-led international coalition dislodged IS from Mosul last month after a nine-month fight for Iraq's second city.
They launched an offensive August 20 to recapture Tal Afar, once a key IS supply hub between Mosul -- around 70 kilometers further east -- and the Syrian border to the west.
IS fighters inside Tal Afar are estimated to number around 1,000.