South African President Thabo Mbeki met for four hours on Friday with Zimbabwean President Robert Mugabe in what sources described as a bid to halt mounting post-election violence and to press for a presidential run-off to be held without delay.

Mr. Mbeki made no statement to reporters after meeting Mr. Mugabe in Harare, and did not meet with the opposition Movement for Democratic Change headed by Morgan Tsvangirai, the official front-runner in the March 29 presidential election. Tsvangirai was expected to tell journalists on Saturday if he would contest a run-off ballot.

The MDC has said it has no confidence in Mr. Mbeki as a mediator and has urged the Southern African Development Community to replace him as point man in the crisis.

The South African Broadcasting Corporation said Mr Mbeki was likely to push for a government of national unity in Zimbabwe. But Mr. Mbeki's proposals seemed likely to fall on deaf ears as Tsvangirai's MDC said it had no interest in meeting with him.

Tsvangirai spokesman George Sibotshiwe said Mr. Mbeki had not informed the MDC in advance of his visit to Harare, and told reporter Blessing Zulu of VOA's Studio 7 for Zimbabwe that the opposition still insists he should step down as crisis mediator.

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