Jan Pronk called the situation in Darfur "critical" and said the government "has to be blamed" for failing to stop attacks outside designated areas where thousands of Sudanese fleeing the violence have gathered.
At a Security Council briefing, he elaborated on Secretary-General Kofi Annan's call for an expanded force and said the Sudanese government should "accept assistance from the international community" if it can't protect its citizens.
Afterwards, when asked about reports that the United Nations was pushing for a 3,000-strong force, Pronk told reporters "three is not enough."
"We need thousands, thousands."
But he wouldn't give a definitive number, saying it's up to the African Union to come up with a recommendation. He urged the 53-nation organization to speed up its decision-making, citing a rise in attacks outside the safe areas.
The African Union (search) currently has about 80 military observers in Darfur, protected by just over 300 soldiers, monitoring a largely ignored cease-fire signed in April.
Arab militias known as the Janjaweed (search) are blamed for violence that has killed up to 30,000 people and forced over 1.2 million to flee their homes in the large region of western Sudan.
The Sudanese government is accused of backing the Janjaweed to put down black African rebel groups that took up arms against the government in February 2003. Khartoum denies backing the militiamen.
On July 30, the council gave the government 30 days to demonstrate that it was taking action to curb the Arab militias and improve security and humanitarian access. It threatened punitive economic and diplomatic measures if Khartoum didn't move quickly.
France, Germany, Russia, Pakistan and other council members reacted positively to Pronk's briefing, calling it balanced. But U.S. Ambassador John Danforth said it shouldn't be up to the Sudanese government to decide whether it can protect citizens.
"The fact of the matter is — and I think Mr. Pronk agrees with this — that the citizens of Darfur have absolutely no confidence that the government of Sudan will protect them and therefore the presence of substantial numbers of monitors, substantial numbers, is absolutely essential," Danforth said.
The U.S. ambassador said Annan and Pronk were "just flat out wrong" for not suggesting that the Sudanese government was responsible for supporting or participating in attacks by the militias, known as the Janjaweed.
"The government of Sudan has been directly involved in military action against civilian villages in Darfur, including within the last week," Danforth said, citing an African Union report confirming Sudanese government helicopter attacks on two villages on Aug. 26.
Sudan's U.N. Ambassador Elfatih Mohamed Erwa claims rebels attacked Sudanese forces when they were redeploying as part of a U.N. plan to improve security.
In his briefing to the council, Pronk said the African Union monitoring force must do more than just investigate past incidents.
"Pro-active monitoring will help to prevent such an incident from taking place," Pronk said. Monitors must "be on the spot, wherever such incidents might occur, 24 hours a day, also in the camps."
Erwa said the Sudanese government had no objections to an expanded mandate for the monitoring force.
"Whether it is 300 or 3,000, if it helps, that's fine," Erwa said.
But Erwa reiterated that Sudan would oppose an international force with another mandate, for example to disarm militias or other groups, as that could lead to military confrontations.