The Turkish army is pushing for a cross-border operation to clamp down on bases of the separatist Kurdistan Workers' Party (PKK) in neighbouring northern Iraq, where, it charges, the rebels obtain weapons and explosives for attacks on Turkish targets across the border.

"NATO shows full solidarity (with Turkey)... and hopes that a solution can be found with a maximum of restraint," De Hoop Scheffer told reporters after talks with Foreign Minister Abdullah Gul here.

His appeal came hours before Prime Minister Recep Tayyip Erdogan was to convene senior government and military officials to discuss measures against rising violence by the PKK.

De Hoop Scheffer ruled out any NATO role in purging northern Iraq of the PKK, listed as a terrorist group by Ankara and much of the international community.

He condemned PKK attacks as "a heinous form of terrorism, which the NATO allies and I reject in the strongest possible form."

De Hoop Scheffer and Gul also discussed Turkish misgivings regarding closer operational cooperation between NATO and the European Union, stemming from Ankara's hostile ties with Cyprus, which is a member of the EU but not NATO.

"We have to further discuss the NATO-EU relationship," the NATO secretary-general said. "I promised Mr. Gul that I'll try to be as constructive as I can... to find a solution which is satisfactory to all parties."

Turkey, a NATO member and a candidate for EU membership, has been blocking Cypriot participation in NATO-EU cooperation discussions.

It wants Brussels to persuade Cyprus to drop its objections to Ankara's bid to become an associate member of the European Defence Agency, which promotes EU-wide defence industry policy.

Turkey refuses to endorse the internationally recognised Greek Cypriot government of the long-divided island. It is the only country to recognise the breakaway Turkish Cypriot statelet in the north of the island.

De Hoop Scheffer was to meet with Erdogan, chief of general staff Yasar Buyukanit and Defence Minister Vecdi Gonul before wrapping up his visit later Tuesday.