Turkey's prime minister on Sunday signaled a joint military offensive with Iran against their common enemy: Kurdish rebels based in northern Iraq. Turkey and Iran were working together and "determined," Recep Tayyip Erdogan said.

"There is no question of any postponement," Erdogan said in a clear reference to a possible joint military operation against the main Kurdish rebel base on Qandil Mountain which sits on the Iraqi-Iranian border deep inside northern Iraq.

"I regret to say this but there will be a price for it," Erdogan said,
apparently referring to possible military losses in a cross-border offensive against the Kurdistan Workers' Party, or PKK, which has been waging a war for autonomy in Turkey's southeast.

It was not immediately clear if the two countries are planning a highly risky and difficult ground offensive at Qandil, which has reportedly been turned into a mine field by the rebels to protect themselves.

The Party of Free Life of Kurdistan, or PEJAK, which is closely affiliated with the PKK, is also fighting against Tehran from Qandil to end what it calls discrimination against Kurds, who make up 14 percent of Iran's population. The U.S.¬ has labeled both Kurdish groups terrorist organizations.

Iranian artillery units often fire salvos at Qandil, and Turkish warplanes stage bombing raids against suspected rebel bases there, but the rebels reportedly rush into deep caves when they hear the whistling shells or the roar of the jets.

The Kurdish provinces of northern Iraq are the country's most stable and prosperous area. But to neighboring Iran and Turkey, both with large Kurdish minorities, they are something else: an inspiration and a support base for the Kurdish rebels in their own countries.

Turkey has already been pressing the U.S.-backed Iraqi government to clamp down on Kurdish guerrillas who use Iraq as a base. The Iranians and Turks fear Kurdish success in creating an autonomous region in northern Iraq, and the prosperity of their enclave, encourages their own Kurdish minorities.

The U.S. ¬has been providing Turkey with intelligence from its Predator drones and now Erdogan says Washington is likely to agree to the deployment of Predators on Turkish soil once its troops leave Iraq at the end of this year.

Turkey already operates some Israeli-made Heron drones to stage pinpoint attacks against the rebels.

Kurdish rebels have dramatically escalated their attacks in Turkey since July, killing dozens of security personnel and at least 10 civilian, including three people in a car bombing in the Turkish capital last week.