The joint Sudan-UN "mechanism has asked the government and the rebels to stop the fighting immediately and the Sudanese government has agreed to comply with this demand as of today", Sudanese Foreign Minister Mustafa Usman Ismail said on Sunday.
He added that the pullback was conditional on rebels halting attacks.
But an African Union (AU) spokesman said on Sunday, citing fresh helicopter strikes against a village in South Darfur state, that the Khartoum government had failed to comply with a deadline to stop fighting in Darfur.
The AU force commander in Darfur, Nigerian General Festus Okonkwo, has told mediators that Sudanese government forces attacked the village of Labado on Saturday, spokesman Assane Ba said.
He added that an AU helicopter had also been fired upon. "This shows that the ceasefire is not being observed."
However, Ba would not say whether rebels or Sudanese government forces were responsible for shooting at AU monitors.
Sudan had been handed a 24-hour deadline on Friday to halt its military offensive or face action from the UN Security Council.
Sudan's Mustafa Ismail said the
rebels too should hold their fire
"Things have changed: the latest report from General Okonkwo is that the Sudan government has not complied. He said government helicopters attacked Labado and burned the place yesterday," Ba said.
Okonkwo had earlier said the Sudanese government was complying with the deadline, which passed on Saturday. The AU had told Sudan to stop hostilities or face having the matter go to the UN Security Council.
AU mediators had a meeting on Sunday with Nigerian President Olusegun Obasanjo, who is also chairman of the AU, but details of their discussions were not immediately available.
The rebel Sudan Liberation Army/Movement (SLA/M) and the Justice and Equality Movement (JEM) had announced they would boycott the Abuja negotiations until Khartoum ended its raids.
Earlier, the AU reported that huge quantities of arms had poured into Darfur and that the government was poised for a major military offensive. The United States, Britain and the United Nations weighed in with warnings to Khartoum and the rebels.
Subsequently, Sudanese Foreign Minister Ismail said the rebels had to withdraw from areas they had entered since an April ceasefire, and refrain from attacks on relief organisations, civilians and their property, and state properties.
"Things have changed: the latest report from General Okonkwo is that the Sudan government has not complied"
African Union spokesman
Sudanese forces would never withdraw from Darfur as a whole because a UN Security Council resolution gave the government responsibility for maintaining security there, he said.
A Reuters correspondent saw an Antonov plane land at Nyala airport in southern Darfur on Saturday and dozens of troops disembark. It was not clear whether they were arriving in the region or had been pulled out from other parts of Darfur.
The United Nations has said Darfur, an area the size of France, is suffering from one of the world's worst humanitarian crises with 2.3 million people in need of aid.