The Iraqi army said on Thursday its forces had retaken full control of the northern town of Shirqat from Islamic State near the extremist militia's stronghold of Mosul.
"Our brave forces have fought a specific battle culminating in the full liberation of Shirqat," Yehia Rassoul, an army spokesman, said.
The official added that Islamic State had suffered "heavy losses," but he did not give details.
"The Armed Forces look forward to the decisive battle in Mosul to teach the terrorist Daesh a lesson," he said, using an Arabic acronym for Islamic State, according to state broadcaster al-Iraqiya.
Government forces, backed by a US-led air alliance, launched on Tuesday a major offensive to recapture Shirqat, around 100 kilometres south of Mosul.
Islamic State seized Shirqat in June 2014 when the al-Qaeda splinter group carried out a blitz attack in northern Iraq.
Shirqat will be the launch pad for Iraq's long-awaited campaign to retake Mosul from Islamic State.