Opening a summit of Southern African regional leaders, South African President Thabo Mbeki expressed optimism Saturday that the gathering could galvanize Zimbabwean power-sharing talks and help produce an historic agreement between the long-ruling ZANU-PF party of President Robert Mugabe and the opposition Movement for Democratic Change.

As summit host and incoming chairman of the Southern African Development Community, the South African president told the heads of state and government that the summit "affords us the possibility to assist the Zimbabwean parties to finalize their negotiations so that together they can ... work to achieve national healing and reconciliation."

Mr. Mugabe sat among the leaders despite the decision by Botswana President Ian Khama to boycott the summit in protest of his attendance following the June 27th presidential run-off election which Mr. Mugabe, the only candidate, won amid widespread condemnation.

MDC founder Morgan Tsvangirai, who outpolled Mr. Mugabe in the March 29 first round of the presidential election but according to the contested official results fell short of a majority, was seated in an observers gallery. Mr. Mugabe and Tsvangirai appeared to hit a deadlock late last week in negotiations on their respective roles in a proposed national unity government.

Those talks continued on the margins of the summit with some speculating that the intense pressure from Mr. Mbeki and other leaders might induce both men to compromise.

Meanwhile, thousands of  Zimbabweans and South Africans protested President Mugabe’s attendance at the summit, as correspondent Benedict Nhlapho of VOA's Studio 7 for Zimbabwe reported from the Johannesburg summit venue.

Some observers concluded that Mr. Mbeki is desperate to bring the two sides together as a vindication of his presidency, set to end next year, and evidence of his statesmanship.

African Studies Professor Sean Jacobs of the University of Michigan told VOA reporter Darren Taylor that although Mr. Mbeki has little to show for his efforts, the MDC delegation at the talks has seemed hesitant to criticize him at this stage of the discussions.

Earlier, Zimbabwean civic leaders criticized what they termed the exclusion of civil society from the power-sharing talks, as correspondent Sylvia Manika reported from Harare.

More reports from VOA's Studio 7 for Zimbabwe...