Iraqi president says Turkish deployment inside Iraq violates international law

But Turkish Prime Minister Ahmet Davutoglu said the troop rotation was routine and the camp had originally been set up in coordination with Iraqi authorities.

A Turkish security source said on Friday the forces would provide training for Iraqi troops near Mosul, which is controlled by Islamic State.

Iraq's prime minister and foreign ministry have called for Turkey to withdraw its forces.

In an online statement, Massoum also called on Turkey to withdraw the troops and asked Iraq's Foreign Ministry to take the necessary measures "to preserve the country's sovereignty and independence".

Islamic State militants overran Mosul in June 2014. A much anticipated counter-offensive by Iraqi forces has been repeatedly postponed because they are tied down in fighting elsewhere.

Davutoglu said the camp, located some 30 km (19 miles) northeast of Mosul, was set up almost a year ago at the Mosul governor's request and in coordination with the Iraqi Defense Ministry.

"This camp was established as a training camp for a force of local volunteers fighting terrorism," he said in a speech to a labor union that was broadcast live by NTV news channel.

"It has trained more than 2,000 of our Mosul brothers, contributing to the freeing of Mosul from the Islamic State terrorist organization," he said.

A senior Kurdish military officer based north of Mosul told Reuters that additional Turkish trainers had arrived at a camp in the area overnight on Thursday escorted by a Turkish protection force.

A small number of Turkish trainers was already at the camp to train a force called Hashid Watani (national mobilization), which is made up of mainly Sunni Arab former Iraqi police and volunteers from Mosul.

The United States was aware of Turkey's deployment of hundreds of Turkish soldiers to northern Iraq but the move is not part of the U.S.-led coalition's activities, according to defense officials in Washington.