UN Secretary-General Kofi Annan on Sunday joined heads of state including Nigeria's Olusegun Obasanjo, chairman of the AU, President Thabo Mbeki of South Africa and Egyptian President Husni Mubarak for the two-day gathering in the Nigerian capital.
The heads of state will base their talks largely on a series of draft resolutions worked out over three days by their foreign ministers, primarily focusing on two proposals to expand Africa's representation on the powerful UN Security Council under planned reforms of the 15-member body.
The summit will also be used to hammer out African solutions to African problems, including the conflicts in the Democratic Republic of Congo and Ivory Coast as well as the humanitarian crisis in the western Darfur region of Sudan.
A decision is also expected on Somalia, where a new government was provisionally installed earlier this month, in a bid to fill a 14-year power vacuum in the Horn of Africa state.
Talks were under way on Sunday morning before the summit between Ivory Coast President Laurent Gbagbo and Mbeki, appointed in November as the AU's mediator in the two-year civil war in the west African state.
The Ivory Coast conflict was the main focus of the AU's Peace and Security Council at a meeting on 11 January in the Gabonese capital Libreville, but little headway was made in reconciling the divided country, the world's top cocoa producer.
Annan, who arrived in Abuja after lobbying for African debt relief at the annual World Economic Forum of the global elite in Davos, Switzerland, was expected to meet with reporters after the opening ceremony at the International Conference Centre.