"It's kind of a chicken and egg situation," Guehenno said. "You need security to bring additional security, but the additional personnel will then contribute to security."

Sudanese President Omar al-Bashir has repeatedly rejected a UN force. But he has come under increasing pressure from the United States, the European Union, some Arab and African countries, and recently China.

Though al-Bashir's government has a history of finding loopholes in agreements with the UN and others, the deal reached Monday appeared to be a significant step forward in bringing a more effective peacekeeping force to Darfur.

Nonetheless, US diplomats and UN officials said they remain cautious until the UN peacekeepers are on the ground in the vast western province where more than 200,000 people have been killed and 2.5 million have been displaced since the conflict began in 2003.

"We'll see whether they've agreed when they actually start to deploy," acting US ambassador Alejandro Wolff told reporters. "We all need to be vigilant - that is understood and agreed by every person in (the) council. ... The test is going to be the implementation."

Wolff also indicated that further Sudanese conditions or delays could lead the council to consider "other measures," presumably additional sanctions.

The United Nations and Sudan agreed in November on the three-stage plan to strengthen the undermanned and under-equipped AU force in Darfur.

The first phase, a light support package including UN police advisers, civilian staff and additional resources and technical support, has already been sent to Darfur. Now that Khartoum has given its approval to the heavy support package, UN and AU officials will start focusing on deployment of the AU-UN force with 17,000 troops and 3,000 police officers.

Al-Bashir has said he would only allow a larger AU force, with technical and logistical support from the United Nations. He has maintained that deployment of UN troops would violate Sudan's sovereignty.

On Monday, after meeting with Malaysia's visiting prime minister, he called for Islamic nations' help in "working with Sudan to face the Western pressures on it to accept international forces."

At the same time, Sudanese Foreign Minister spokesman Ali al-Sadiq said Monday Sudan has also agreed to the larger deployment. But he said the UN had to send a team to Khartoum and a "tripartite committee" of UN, AU and Sudanese experts will decide on the details and timing of the entire force.

"This is a very significant step to solving the problems in Darfur," al-Sadiq said. "We hope it will ease the pressure."

Guehenno said there is already an agreement that the commander and deputy commander of a hybrid force will be Africans, along with the secretary-general's special representative. But he said "the command and control structures will be provided by the United Nations."

The UN-AU force will be looking for African troops, Guehenno said, but if the UN can't find enough "we will be looking elsewhere."

1

2