Kurdish authorities in the northern Iraqi city of Irbil are seizing millions of dollars worth of trucks, computers and communications equipment from the United Nations, delaying U.N. plans to establish a permanent office in northern Iraq to manage its political and humanitarian operations there, according to senior U.N. officials.

Kurdish officials said any equipment that was purchased with Iraqi oil revenue under Saddam Hussein's government belongs to the Iraqi people, according to U.N. officials. The United Nations had initially agreed to transfer the equipment to the local authorities in Irbil, only to reverse position and demand it be returned, the Kurdish officials said.

The former Iraqi president was required to use his country's oil wealth to underwrite a massive U.N. humanitarian aid program in Iraq between December 1996 and May 2003. Iraq spent more than $36 billion on goods through the U.N. oil-for-food program and funded the activities of 900 international staffers and about 2,500 local Iraqi employees throughout the country.

The United Nations abruptly pulled out of Iraq last year, after two terrorist attacks against the United Nations' Baghdad headquarters. It left behind millions of dollars' worth of vehicles, computers and other equipment in its offices in Baghdad, Basra and Irbil. U.N. officials in Jordan, and Kuwait continue to manage the organization's assets and relief operations from outside Iraq through a network of Iraqi employees.

The seizures began on June 21, after the Kurdistan regional government's prime minister, Nechirvan Barzani, a nephew of prominent Kurdish leader Massoud Barzani, ordered the requisition of vehicles and other equipment belonging to six U.N. agencies, including the U.N. Development Program and the World Health Organization, a senior U.N. official said.

"They seized 40 vehicles, 400 to 500 communications items, everything from walkie-talkies to satellite units," said Fred Eckhard, the chief spokesman for U.N. Secretary General Kofi Annan. Eckhard said Kurdish authorities also took "200 computers, printers, copiers, air conditioners and other office equipment. In addition, they went to the U.N. storehouse, broke the padlocks, replaced them with their own locks and said these are now their assets."

U.N. officials said the Kurdish action comes several months after a separate Kurdish faction headed by Jalal Talabani, the leader of the Patriotic Union of Kurdistan, claimed the United Nations' property in Sulaymaniyah. At the time, the United Nations was in the process of transferring some of the assets to the local Iraqis, according to a senior U.N. official. "The secretary general instructed us, 'Don't keep anything you won't need for the reasonable scope of activities,' " the official said. "We were ready to transfer them, and they came in and took over everything."

Annan's top humanitarian relief official for Iraq, Ross Mountain of New Zealand, protested the latest action in Irbil in a letter to the local administrator, noting that "under international law" the United Nations was the rightful owner of the property, according to a report released Friday by Annan.

"They contend that since these had been purchased with funds from the oil-for-food deal program and donor contributions, they were not U.N. property," Annan wrote. "The local authorities have now expanded the scope of the seizures, taking over all U.N. assets regardless of their source of funding."

Mohammed Ishan, a minister for human rights in the Kurdistan Regional Government, said the allegations that the local government forcibly seized the equipment are "not true."

He said the United Nations and the U.S.-led occupation authorities transferred the equipment in June to local authorities, who then distributed it to the various ministries that carried out humanitarian programs with the United Nations. He said U.N. officials in Jordan then "changed their minds."

Ishan said Kurdish authorities protected the U.N. headquarters and its possessions in Irbil throughout the war, preventing looting that occurred elsewhere in Iraq. He said the United Nations "thanked us for protecting their property and authorized us to keep them."

The property squabble comes as the United Nations is preparing to establish its first permanent bases of operations in Baghdad, Basra and Irbil since last year's attacks, which killed 22 U.N. officials and associates, including top envoy Sergio Vieira de Mello of Brazil.

Although the United Nations has postponed plans to set up an office in Irbil, it is pressing ahead with plans to send a small team, headed by Vieira de Mello's successor, Ashraf Jehangir Qazi of Pakistan, to Baghdad before mid-August. The new mission will be limited to essential U.N. staff required to pave the way for a national conference on Iraq's future and to prepare for January elections.

But U.N. officials said an effort to assemble an international force to defend a larger U.N. presence has stalled, forcing them to maintain a limited presence and to rely on the United States and its military allies for security.

"Staff security remains the overriding constraint for all United Nations activities," Annan wrote. "For the foreseeable future, the United Nations will remain a high-value, high-impact target for attack in Iraq."