The United Nations and the African Union have tentatively agreed on the outline of a joint peacekeeping operation for Darfur. But as VOA's Peter Heinlein reports from U.N. headquarters, the 23,000 strong force faces several obstacles that will delay deployment until at least the middle of next year.

Diplomats and peacekeeping officials Wednesday reacted cautiously to the deal, which still must be approved by the U.N. Security Council, the African Union Peace and Security Council, as well as the Sudanese government.

The plan envisions deployment of a hybrid force in Darfur under joint U.N. and AU control as early as next year. The force would be more than three times the size of the 7,000 strong African Union mission that has been largely ineffective in stopping violence in a region the size of France.

But the deal laid out in a report to the Security Council Wednesday glosses over several thorny issues, including how a joint command and control arrangement would work.

On paper, the African Union would have day-to-day operational command of the hybrid force, while overall control would rest with the United Nations.

Assistant Secretary General for Peacekeeping Operations Hedi Annabi admits, however, that the concept will be difficult to implement.

"This is unchartered territory we're moving into. We have never done a hybrid operation," said Annabi. "And any military expert will tell you that the more hybrid it gets, the more difficult in terms of command control arrangements it becomes because you have two organizations that have to coordinate everything."

A senior U.N. official Wednesday said the hybrid force would be drawn largely from four countries, two in Africa and two outside. The official, who asked not to be identified, said the four were selected because they are likely to be acceptable to the government of Sudan, which must approve the deal.

Sudan has previously rejected the idea of U.N. troops in Darfur, insisting that any peacekeeping force be under African control.

The official said Sudan would be pressured to accept the hybrid force deal at a three-way meeting with U.N. and AU representatives next week in Addis Ababa.

But Assistant Secretary General Annabi says even in the event that Sudan says 'yes' to the deal, it will be a year before the force can be operational.

For the hybrid, I think if we start moving to the hybrid in the first part of next year, realities being what they are, it will take time. It's not going to happen overnight," said Annabi. "As frustrating as it is for all of us.

Those frustrations have been on display among several Security Council members pushing for increased U.N. sanctions against Sudan, including a country-wide arms embargo, and a complete ban on Sudanese military flights over Darfur. Supporters say they lack the necessary nine votes on the Council to win adoption of the sanctions.

Experts say at least 200,000, and possibly as many as 400,000 people have died since Darfur's civil war broke out in early 2003. More than two million others have been forced to flee their homes to avoid the carnage, which the United States has labeled genocide.