The 30-vehicle convoy left Ankara for Silopi, the sources told AFP, adding that it was now close to Adana province in southern Turkey.
The deployment came as Iraq said its forces had entered Daesh-held Mosul for the first time since the terrorist group overran the city more than two years ago.
Ankara has repeatedly insisted that it would be involved in the offensive in northern Iraq and would be "at the table".
Defence Minister Fikri Isik said Tuesday's deployment was a part of Turkey's preparation for "important developments in the region", referring to Kurdish rebels inside the country and events in Iraq.
"Turkey is preparing in advance for whatever happens (and) this is one element of that," he said, quoted by the official news agency Anadolu.
The outlawed Kurdistan Workers' Party (PKK) has waged an insurgency inside Turkey since 1984, with almost daily attacks against Turkish security forces in the mainly Kurdish southeast.
Isik added that there was a "serious fight against terror" inside Turkey, a reference to Daesh and the PKK.