Sudan's government has warned that Darfur peace talks are in danger of collapsing as rebels hold out against signing a key element of a deal to end the crisis.
The United Nations said on Monday up to 10,000 people were dying each month from disease and violence in camps for those displaced by the fighting.
The African Union, which is hosting talks between the rebels and Khartoum in the Nigerian capital Abuja, made a last ditch attempt yesterday to break a deadlock in the negotiations which have become bogged down in squabbling over security issues.
The rebels have said they will not sign a humanitarian deal with the Sudanese government until key security issues are agreed, including the disarmament of the pro-government Arab Janjaweed militia.
The two sides have already agreed on a deal to cooperate on allowing greater access for humanitarian agencies and setting up a joint humanitarian monitoring unit, but have not signed the pact.
African Union chairman and Nigerian President Olusegun Obasanjo summoned both sides yesterday for an emergency meeting.
"I can't say the deadlock is broken. Actually we met with President Obasanjo and we stated our position about why we are not willing to sign the humanitarian protocol," said Ahmed Mohammed Tugod, negotiator for the Justice and Equality Movement, one of the two rebel groups.
Tugod said Obasanjo had asked the rebels to reconsider overnight and come back to the negotiating table on Wednesday.
Sudanese government officials leaving the meeting said the talks might be called off if the rebels had not changed their position by then.
"By tomorrow we will have a clear position from the rebels that determines whether the talks continue or not," said the Sudanese government delegation's leader, Majzoub al-Khalifa.
The rebels took up arms against the government in February 2003 after years of low-intensity fighting between Arab nomads and mainly African farmers in the arid western province.
They accuse Khartoum of arming the Janjaweed to loot and torch African villages, a charge the government denies. It says the Janjaweed are outlaws.
More than a million Darfuris have fled their homes to escape attacks by the Janjaweed. The United Nations estimates at least 50,000 people have been killed in the conflict.