"Turkey's cross-border operation is a result of its legitimate right to self-defence," Erdogan said in a televised speech to the parliamentary group of his Justice and Development Party (AKP).

"Turkey is in a rightful struggle against the terrorist organization that is threatening regional peace and stability... Turkey has the right to defend itself, eliminate those that harm its citizens' peace, unity and solidarity," he said.

Turkish forces stormed into northern Iraq on Thursday evening to flush out an estimated 4,000 Kurdistan Workers Party (PKK) rebels who Ankara says have found refuge in the autonomous region and use it as a springboard for their armed separatist campaign in southeast Turkey.

Both the United States and Iraq have in recent days issued repeated calls for the incursion to be wrapped up as swiftly as possible, so as to avoid destabilising the region.

Baghdad has labelled the incursion a "threat" to its sovereignty.

Turkey says it will withdraw its troops once they achieve their objective of flushing out the rebels and destroying their camps, but has given no timeframe.

The PKK is listed as a terrorist group by Turkey, the European Union and the United States.

Erdogan argued that the PKK presence was a source of "political instability" for Baghdad and gave fresh assurances that Turkey's military action had no aim other than routing the rebels.

"This operation is not against northern Iraq but only against the terrorist organization... Turkey has always supported the protection of Iraq's territorial integrity, sovereignty and political unity," he added.

The Turkish army says it has so far killed 153 rebels and lost 17 soldiers in the offensive.

The PKK has been fighting for self-rule in Turkey's mainly Kurdish southeast since 1984 in a conflict that has claimed more than 37,000 lives.