Baghdad says the deployment was conducted without its approval and labels it 'a hostile act'

Iraq's Foreign Ministry summoned the Turkish ambassador on Saturday to demand that Turkey immediately withdraw hundreds of troops deployed in recent days to northern Iraq, near the Islamic State-controlled city of Mosul.

The ministry said the Turkish forces had entered Iraqi territory without the knowledge of the central government in Baghdad, and that Iraq considered such presence "a hostile act".

But Turkish Prime Minister Ahmet Davutoglu said the troop rotation was routine and that Turkish forces had set up a camp near Mosul almost a year ago in coordination with Iraqi authorities.

"This camp was established as a training camp for a force of local volunteers fighting terrorism," he said.

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

Iraq has urged the international community to provide more weapons and training in its battle against IS, but rejects most forms of direct intervention, mistrusting the intentions of foreign powers.

Davutoglu said the camp, located 30 kilometers northeast of Mosul, was set up at the Mosul governor's request and in coordination with the Iraqi Defense Ministry.

"It has trained more than 2,000 of our Mosul brothers," he said.

Iraqi President Fouad Massoum earlier described the deployment as "a violation of international norms and law" and called on Turkey to withdraw.

A senior Kurdish military officer said 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 made up of mainly Sunni Arab former Iraqi police and volunteers from Mosul.

Washington was aware of Turkey's deployment of Turkish soldiers to northern Iraq but the move is not part of the US-led coalition's activities, US defense officials said.