Zimbabwe's ruling and opposition parties have moved closer to formal negotiations on a power-sharing deal.
Talks on ending the country's ongoing political crisis had stalled, but it appears a key sticking point has been resolved.
Opposition leader Morgan Tsvangirai had insisted another mediator join South African President Thabo Mbeki in efforts to help solve Zimbabwe's political crisis.
Mr. Tsvangirai had accused the South African president of favoring Zimbabwe President Robert Mugabe.
The South African president has agreed to accept help in his mediation efforts from representatives of the African Union, United Nations, and the Southern African Development Community.
Mr. Tsvangirai welcomed the move, which was announced after Mr. Mbeki met on Friday with African Union and U.N. officials.
Saturday Mr. Tsvangirai met with AU Commission Chairman Jean Ping about moving forward with formal negotiations.
Mr. Tsvangirai has also insisted that conditions for formal negotiations include an end to violence against his political supporters and the release of political prisoners.
Mr. Mugabe was re-elected last month in a widely-condemned, runoff vote in which he was the only candidate.
Mr. Tsvangirai dropped out of the race after many of his supporters were wounded, jailed or killed in what he said was a state-sponsored campaign of intimidation.
Some information for this report was provided by AFP.