Describing the increasingly tense situation on the Turkish-Iraqi border as "dead serious," Iraqi Foreign Minister Hoshyar Zebari said Baghdad was becoming "extremely nervous and worried" at the Turkish military build-up in the area.

Turkey has threatened a military incursion across the border against bases belonging to the Kurdistan Workers' Party (PKK), which has been waging a long-term struggle for self rule in eastern Turkey.

Zebari said that Turkey "was not responsive" when Iraqi officials flew to Ankara for talks on how to resolve the situation.

Turkey insists that the only way to avoid an incursion is for Iraq and the United States to crack down on the PKK bases on Iraqi territory.

But Zebari argued that Turkish demands for PKK leaders to be rounded up and handed over were unrealistic.

"They are not under our control in fact. They are up in the mountains, they are armed," he said.

Turkey has in the past engaged in cross-border "hot pursuit" operations against PKK fighters, but Zebari said the scenario had shifted dramatically in recent weeks.

"They are talking about large scale military incursion which is getting people extremely, extremely nervous and worried," he said.

Such an assault would have "disastrous consequences" and meet with stiff Iraqi resistance, he warned.

"That's why the whole government of Iraq and the whole people of Iraq are united really not to see their sovereignty, their territorial integrity undermined by a friendly neighbouring country," he said.