African Union (AU) spokesman Assane Ba said on Sunday that the non-arrival of some delegates of the rebel Sudan Liberation Movement (SLM) was the major cause for the delay.
SLM spokesman Abd al-Jabar Duba confirmed that the arrival of some of the group's delegates was still being awaited in the Nigerian capital Abuja.
Earlier, a spokesman for another rebel group, the Justice and Equality Movement (JEM), said his group might have to quit talks before they have even begun.
JEM's Ahmad Husain Adam said the threat to pull out of talks comes as the government embarks on a military campaign against JEM forces in Darfur.
He called for the implementation of the two security and political protocols that have been signed between the two sides.
Meanwhile in Cairo, Sudanese President Umar al-Bashir discussed with his Egyptian counterpart Husni Mubarak developments in Sudan and efforts to find a settlement to the crisis in the Darfur region.
Arab League follow-up
On another issue related to Darfur, Aljazeera has learned from Arab League sources that the closing statement issued by the ministerial committee entrusted to follow up on decisions of the Tripoli summit concerning the Darfur crisis, would include the following key points:
• Stress the commitment to the ceasefire by all parties involved.
• Cooperation with the Arab League and the African Union to find a settlement to the Darfur problem.
• Raising the level of representation in the Abuja talks.
• Seeking a full meeting to arrange for a comprehensive reconciliation between various tribes in the Darfur region.
• A follow-up meeting in Libya on 15 January.