Turkish President Recep Tayyip Erdogan said on Tuesday that Ankara could not continue the peace process with the Kurds amid continuing attacks against Turkish targets.

"It is not possible to carry on the (peace) process with those who target our national unity and brotherhood," he said, referring to the outlawed Kurdistan Workers' Party (PKK).

Turkey, which considers the PKK a terrorist organisation, launched peace negotiations with the group's jailed leader Abdullah Ocalan in late 2012, but the two sides have yet to reach an accord.

Ankara has expanded the cross-border campaign against the Islamic State (IS) group in Syria, beginning last week to include PKK positions in northern Iraq, after deadly attacks inside Turkey blamed on the Kurdish separatists.

Late on Monday, gunmen in a predominantly Kurdish part of eastern Turkey shot dead a paramilitary police commander -- the latest attack that Erdogan has blamed on Kurdish militants.

"Those who exploit the people's and the state's tolerance and patience will receive the answer they deserve as soon as possible," he said.

Erdogan vowed that Turkey's operations against Kurdish militants and Islamic State jihadists would continue "with determination".

"Any step back is out of the question. This is a process and this process will continue with the same determination," he told reporters at an Ankara airport before leaving for China on an official visit.

He also voiced hope that NATO, which is holding an emergency meeting on Tuesday, would take necessary steps. "Turkey will use whatever rights stemming from international law till the very end" to protect itself from attacks, he added.

Turkey is likely to face questions at the NATO meeting over its decision to lump its campaigns against the Kurds and IS together into a broad "war on terror", even though the secular Kurdish groups and the Islamist IS are themselves bitterly opposed.

Erdogan also said the formation of a safe zone in the north of war-torn Syria, free from IS, would help the return of many refugees.

"The clearance of those regions and the creation of a safe zone there will lay the ground for 1.7 million citizens here to return home," he said.