According to Reuters, Iranian-backed Iraqi Shi'ite paramilitary groups have said they have started an offensive against Islamic State positions west of Mosul, which will target Tal Afar.
Speaking to reporters at a reception marking Republic Day in Ankara, Erdogan said the information he received had not confirmed such movement. He gave no details on the numbers of reinforcements, or what the different response would be.
Ankara has repeatedly warned that it would take measures if there is an attack on the city, which has a sizeable ethnic Turkmen population, as part of a wider U.S.-led offensive to retake Iraqi city of Mosul from Islamic State.