A United Nations investigation on whether genocide has been committed in Sudan's Darfur region has been submitted but not made public.
Conditions in refugee camps are improving
It is first being sent to UN Secretary General Kofi Annan, before being released next week, a UN official said.
Meanwhile, fewer people are dying from disease as Darfur's refugee camps have become better equipped, the World Health Organisation says.
Some 70,000 people, mostly non-Arabs, have died in the two-year conflict.
More than 1.5m have fled their homes, with many saying they have been attacked by horse- and camel-mounted Arab militias backed up by the security forces.
The Sudan government denies backing the Janjaweed militias and blames rebels for starting the conflict.
The US has said that genocide is being committed and has again started to lobby for a UN resolution threatening sanctions against Sudan, it says.
Previous attempts to threaten sanctions have been blocked by China, which has oil interests in Sudan, and Russia, which has sold arms to the government, according to lobby group Human Rights Watch.
WHO crisis chief David Nabarro said he believed that the death rate in Darfur was now far lower than the 10,000 a month which had been reported.
"The kinds of information that I am receiving on water supply, sanitation, food access and health services... would mean that the death rates are likely to have reduced," he told reporters.
However, a new mortality study has not been carried out because the area is too dangerous, he said.
Following the signing of a deal to end a separate war in southern Sudan, the European Union has offered 50m euros ($65m) in aid, to be divided equally between the north and south.
The EU, the world's leading aid donor, suspended cooperation with Sudan in 1990.
Southerners hope their 21-year war is over
A further 400m euros ($520m) is available if peace is restored to Darfur, reports the AFP news agency.
EU aid commissioner Louis Michel said the first tranche of money was needed to "to show the people of Sudan... that there is a dividend to peace".
"We are committed to use the same drive and to draw from our experience in resolving the conflict in southern Sudan to bring a prompt and fair answer to the conflict in Darfur," said Sudan's Vice-President Osman Ali Taha.
Russia has said that it will participate in the planned peacekeeping operation in southern Sudan.
The UN hopes to send some 10,000 troops but the mainly Christian and animist former rebels are wary of having too many Muslim soldiers.
In another development, a leading human rights activist has been arrested, according to his wife.
Madhawi Ibrahim Adam was arrested early on Monday in Kordofan state, which borders Darfur.