UNITED NATIONS — Facing its most ambitious peacekeeping deployment ever in Darfur, the United Nations soon might face “humiliation” — as the Sudanese government, rebel groups, troop- and equipment-contributing countries, the U.N.’s own peacekeeping department, and the General Assembly’s budgetary organ blame each other for the force’s failure, officials say.

The head of the U.N. peacekeeping department, Jean-Marie Guéhenno, yesterday said that beyond such humiliation in Darfur, all U.N. peacekeeping may face a “setback” if the mission there fails. Speaking at the Security Council, he detailed the hardships in deploying 26,000 troops under the joint command of the U.N. and the African Union. The mission lacks critical equipment, such as at least 18 helicopters to move the troops around in the vast Darfur area, and no contributors have offered any. Khartoum, meanwhile, has banned several countries from contributing troops and know-how. Also, Darfur rebels told engineers from Sudan’s ally China that they were unwelcome.

American officials privately are expressing frustration at the slow pace of peacekeeping department’s planning and execution of the Darfur deployment. But on the General Assembly’s budget committee, some criticized a $250 million contract that was awarded to a California-based subsidiary of Lockheed Martin to build infrastructure for the mission — which U.N. officials say they needed to award on a no-bid basis to hasten the deployment at Darfur.

Meanwhile, in Darfur, little hope exists that on January 1 — when the so-called “hybrid force” is scheduled to replace an 8000-troop force under sole command of the African Union — it will have the capacity to do much better in protecting civilians than its “inadequate” predecessor.

The U.N. peacekeeping chief, Mr. Guéhenno, was doubtful about the capacity of the force. “Do we move ahead with the deployment of the force that will not make a difference, that will not have the capacity to defend itself, and that carries the risk of humiliation of the Security Council and the United Nations, and tragic failure for the people of Darfur?” he said.

Khartoum has refused to accept peacekeeping units from Thailand and Nepal, as well as aid from a Nordic engineering company, Mr. Guéhenno told the council. Sudan’s aviation authorities also declined to license certain flights and banned all night flights. Khartoum even reneged on a previous agreement to allow the units to wear blue U.N. berets, he said.

Sudan’s ambassador, Abdalmahmood Abdalhaleem Mohamad, dismissed such disagreements as “small details,” and said that while his country has agreed to accept a “hybrid” force, it also insists that the force will have an “African character,” as called for by the resolution that created it. The United Nations, he argued, is yet to “exhaust” all potential African contributors for the force. Sudan has rejected any helicopters or other contributions from Britain and America. But Mr. Mohamad denied reports his country also has rejected special troops from Egypt, a neighboring country in several ongoing disputes with Sudan.

Meanwhile, the awarding of the six-month no-bid contract with the Lockheed subsidiary, Pacific Architects and Engineer — a frequent a contractor with the State Department and the United Nations — has been portrayed by Mr. Mohamad as the latest proof of America’s intention to use the crisis to dominate his country.

The contract, however, was also criticized at the General Assembly budgetary committee by diplomats from Singapore, Canada, and Russia. They raised questions as to whether U.N. procurement rules were followed. A November 8 report by the U.N.’s budget advisory committee on the new force’s proposed $1,477,766,300 budget, however, noted that the secretary-general can “waive formal methods” when there is an “exigency requirement” to do so. Critics of the no-bid contract, however, point to a 2002 report by the U.N.’s watchdog that accused PAE of overcharges in carrying a peacekeeping contract in Congo.

Washington increasingly believes that the hybrid force is the answer to the Sudan crisis. The American ambassador to the United Nations, Zalmay Khalilzad, said yesterday this commitment included calls made by the State Department to world capitals, urging them to contribute to the force.

But according to the International Crisis Group’s vice president, Donald Steinberg, the State Department’s involvement rarely goes beyond that of the assistant secretary of state for African affairs, Jendaye Frasier.

“We are involved at the highest levels,” Mr. Khalilzad countered.