The United Nations' special envoy to Sudan called on Khartoum on Wednesday to invite thousands of African peacekeepers to help resolve a humanitarian crisis in Darfur, citing the government's failure to stop rampaging Arab militia from carrying out deadly attacks against hundreds of thousands of displaced black civilians.

But the U.N. envoy, Jan Pronk of the Netherlands, told the Security Council in a report that Sudan has made "some progress" in disarming the militias and in increasing security for homeless Darfurians in some camps, a finding that diplomats said is likely to spare Khartoum from facing immediate Security Council sanctions.

The 15-nation council threatened on July 30 to consider imposing economic and diplomatic sanctions on Sudan if it failed to disarm the militia known as the Janjaweed and arrest and prosecute its leaders within 30 days. But the deadline passed without any council action and today's 14-page report -- which will be debated by the council Thursday -- said that making Darfur "safe and secure" cannot be accomplished in one month.

"Attacks against civilians are continuing and the vast majority of armed militias has not been disarmed," Pronk wrote. "Similarly, no concrete steps have been taken to bring to justice or even identify any of the militia leaders or the perpetrators of these attacks, allowing the violation of human rights and the basic laws of war to continue in a climate of impunity."

The U.N. report calls on Sudan to accept a U.N. proposal to allow about 4,000 African Union peacekeepers and police officers to help monitor a cease-fire between the government and the rebels. Although Sudan would continue to bear primary responsibility for ensuring the safety of its people, the African troops should be given the authority to "protect civilians whom it encounters under imminent threat and in the immediate vicinity, within its capability," Pronk said.

Sudan has allowed a contingent of about 300 Rwanda and Nigerian peacekeepers and observers in Darfur, but it refused requests from the African Union to expand the mission and provide them with the authority to protect civilians in Darfur. Nigerian-sponsored peace talks between the government and rebels in Abuja, Nigeria, are expecting to take up the matter again in the coming days.

The report took some steam out of the Bush administration's efforts to maintain the threat of sanctions over Sudan if it failed to crack down on the militia, diplomats said. But John C. Danforth, the U.S. ambassador to the United Nations, said last week that the United States would press the council to consider sanctions against Sudan if it refuses to permit more African peacekeepers.

But other key council members, including Pakistan, oppose the adoption of any resolution that would compel Sudan to accept a larger mission. "Sanctions is not a good choice," said Russia's U.N. ambassador, Andrey Denisov. Although Sudan's performance "is still far from being satisfactory," Khartoum has made some "very steady, very slow progress."

Sudan's U.N. ambassador, Elfatih Erwa, said that U.N. report is "balanced," if you read in its entirety. "Like the United States in Iraq, we are limited as to what we can do," he said. "There were some things that we were unable to fulfill due to the circumstances in the security side."

Pronk stopped short of accusing the government of sponsoring the Janjaweed, which is believed responsible for killing as many as 50,000 civilians and driving more than 1 million people from their homes. He said that the United Nations was unable to verify refugee accounts that government troops and the militia collaborated in attacks on local villages. The Bush administration, human rights organizations and Sudanese refugees charge Sudan's armed forces have recruited, armed and backed the militia.

The crisis in Darfur began in February 2003, when two rebel groups, the Sudanese Liberation Army and the Justice and Equality Movement, staged a series of attacks on government installations, citing discrimination against Darfur's main black African tribes, the Fur, Zaghawa and Masalit. U.S. officials and human rights observers maintain that the government responded with disproportionate force, organizing and backing Arab militia that launched a campaign of ethnic cleansing in Darfur.

Displaced Sudanese women wait in line under a hot sun at a food-distribution center in Deesa.