"The spokesman of the Joint Operations Command denies Turkish participation of any kind in operations for the liberation of Nineveh," a statement said, referring to the Iraqi province of which Mosul is the capital.
Turkish Prime Minister Binali Yildirim told reporters Sunday that Turkish troops stationed outside Mosul had provided support "with artillery, tanks and howitzers" following a request by Kurdish peshmerga forces.
Thousands of peshmerga forces are currently involved in a massive push in the Bashiqa area northeast of Mosul, where Turkey has a military base.
The forces of the autonomous Kurdish region, whose leader has close ties with Turkey, have complained recently that the US -led coalition's air support as insufficient.
Turkey had repeatedly stated it wanted a part in the massive operation to retake Mosul, Daesh's last major stronghold in Iraq.
Turkish presence in northern Iraq is not new but reinforcement sent to the Bashiqa base last year sparked the ire of parts of Iraq public opinion and of dominant Shiite parties.
AFP reporters on the front line near Bashiqa saw artillery fire emanating from the Turkish base and targeting Daesh positions on several occasions since the offensive started a week ago.
Iraqi Prime Minister Haider al-Abadi is under domestic pressure not to be seen as tolerating the presence on his soil of troops from a country many in Iraq see as having abetted the rise of the terrorist group.
US Defense Secretary Ashton Carter visited Baghdad Saturday and Irbil, the Kurdish capital, Sunday.
He had suggested before his visit to Iraq that Turkey should be given a role in the Mosul offensive, Iraq's biggest military operation in years.
But speaking after a meeting with Carter, Abadi swiftly rejected the idea.
"I know that the Turks want to participate ... We tell them 'thank you, this is something the Iraqis will handle and the Iraqis will liberate Mosul,'" he said.