The Sudanese government gave the green light Monday for the deployment of attack helicopters and more than 3,000 U.N. troops, police, and other personnel to beef up the 7,000-strong African Union force in conflict-wracked Darfur.

Sudan's U.N. Ambassador Abdalmahmood Abdalhaleem informed Secretary-General Ban Ki-moon in a letter that the government had approved the U.N. plan to send helicopter gunships, the last outstanding item in the U.N.'s "heavy support package" for the AU force.

"It is the sincere hope of the Sudan that implementation of the heavy support package would proceed expeditiously," Abdalhaleem said.

The Sudanese letter arrived as Ban headed into meetings on Darfur with AU chief executive Alpha Oumar Konare and the two envoys trying to promote a political settlement of the four-year conflict in the western Sudanese region, the U.N.'s Jan Eliasson and the AU's Salim Ahmed Salim.

Sudan sent a copy of the letter to the president of the U.N. Security Council and it was circulated to members who were scheduled to meet informally later Monday with Konare and the two political envoys.

The official Saudi news agency, SPA, reported Sunday that Sudanese President Omar al-Bashir phoned Saudi King Abdullah and told him the Sudanese government had signed a joint agreement with the U.N. and the AU that defines their respective roles in Darfur.

It quoted the king as saying the agreement "will support Sudan's unity, security, stability and peace" but gave no details.

Abdullah, Ban, and Arab League chief Amr Moussa, met al-Bashir at an Arab summit in Riyadh last month to discuss the introduction of U.N. peacekeepers into Darfur.

More than 200,000 people have been killed and 2.5 million have been displaced in the four-year conflict in Darfur, which began when rebels from ethnic African tribes rose up against the central government. The government is accused of responding by unleashing the janjaweed militias of Arab nomads — blamed for indiscriminate killing. The government denies the charges.

The United Nations and Sudan agreed in November on a three-stage plan to strengthen the undermanned and under-equipped AU peacekeeping force in Darfur. It was to culminate in the deployment of a joint AU-U.N. force with 17,000 troops and 3,000 police officers.

The first phase, a light support package including U.N. police advisers, civilian staff and additional resources and technical support, has already been sent to Darfur.

The U.N., AU and Sudan agreed on a second phase last Monday — including more than 3,000 U.N. troops, police, and other personnel as well as substantial aviation and logistics equipment. But Sudan rejected a proposal to include six attack helicopters.

Sudan's approval of the helicopter component will now allow the heavy support package to be deployed.

Al-Bashir has backed off from the final stage, saying he would only allow a larger AU force, with technical and logistical support from the United Nations. He maintains that deployment of U.N. troops would violate Sudan's sovereignty.