Iraq on Tuesday barred Turkish Energy Minister Taner Yildiz's plane from landing in Arbil, capital of the autonomous Kurdistan region, in the latest sign of worsening ties between the once-close neighbours.
The incident highlighted chilly ties between Baghdad and Ankara, in part due to issues related to Iraqi Kurdistan, and rows between the Iraqi federal government and the Kurds over energy contracts and disputed territory.
"This flight did not obtain the necessary legal approvals, and it was therefore decided to prevent it from landing at Arbil airport," Nasser Bandar, the head of Iraq's civil aviation authority, told AFP.
Though Kurdistan is autonomous, Bandar said the federal government retains control over all Iraqi airspace.
An official from the Kurdistan regional government confirmed on condition of anonymity that Yildiz's plane was not permitted to land, adding the minister was on his way to Arbil for the completion of an oil and gas development deal.
Kurdistan government spokesman Safin Dizai said Baghdad attributed the move to a technical problem, and that the region hoped there was no other reason for barring the minister's entry to Kurdistan.
Yildiz was headed for Kurdistan to attend an oil and gas conference, where he was to give a speech, he said.
Kurdistan and the federal government are at odds over several issues including energy contracts the region has signed with foreign companies without Baghdad's approval, territory in north Iraq that Kurdistan wants to incorporate over Baghdad's strong objections, and power-sharing.
On the ground, tensions between the two sides have been running high in north Iraq, and reinforcements have been sent to disputed areas.
The Iraqi Kurds said on Friday that talks between federal and Kurdish security officials aimed at easing the tensions broke down over Baghdad's refusal to scrap the Tigris Operations Command, a federal military command that covers disputed territory in north Iraq.
Iraqi Prime Minister Nuri al-Maliki warned in remarks the following day that: "If conflict erupts, it would be unfortunate and painful, and it will be an ethnic conflict" that is "not in the interest of Kurds nor Arabs nor Turkmen."
Ties between Baghdad and Ankara have also been strained by Turkey's refusal to extradite fugitive Iraqi Vice President Tareq al-Hashemi and disagreements over the conflict in their common neighbour Syria.
Turkish Premier Recep Tayyip Erdogan has accused the Iraqi government of trying to drag the country into civil war, amid the rising tensions between Baghdad and Iraqi Kurdish forces.
Maliki, for his part, has said Turkey was treating the Kurdistan region, with which it has close economic ties, like an "independent state."
Baghdad has also strongly objected to air strikes which Ankara has carried out against Turkish Kurdish rebels in Iraqi Kurdistan and has accused Turkey of accepting "illegal" transfers of crude oil from the Kurdish region.