A spokesman for South African President Jacob Zuma did not comment on a possible visit, but said in a statement that a delegation of mediators sent by Zuma was leaving for Zimbabwe and expected to arrive late Sunday.
"We want to thank the government of South Africa, in particular President Zuma, for helping us," Zimbabwean Prime Minister Morgan Tsvangirai told about 30,000 people at a party rally in Harare. "They still continue monitoring what we are doing here in Zimbabwe."
Tsvangirai, the country’s longtime opposition leader, entered into a power-sharing agreement in February with President Robert Mugabe, who has ruled the country since its 1980 independence from Britain.
South African and other regional leaders had pushed for the coalition following a series of inconclusive elections marred by violence blamed on Mugabe’s loyalists, urging the longtime rivals to work together to end their nation’s political and economic crises.
But Tsvangirai temporarily withdrew from the unity government in October, cited the prosecution of one of his top aides among other issues. He returned three weeks later after receiving assurances that South Africa’s president would intervene.
"People should not live in fear of violence or being beaten by police" because they support Tsvangirai’s party, he said at Sunday’s rally. "This must end."
Mugabe, in turn, accuses Tsvangirai of doing too little to persuade Western governments to lift foreign bank account freezes and other sanctions imposed on Mugabe and his top aides.
Tsvangirai said Sunday that instability in Zimbabwe also had affected South Africa, sending millions of economic refugees and political asylum seekers across the border.
South Africans "want to see us fulfill all that we have agreed," Tsvangirai said.
Tsvangirai has said that Zuma’s predecessor took too soft a line on Mugabe. Thabo Mbeki, the regional point man on Zimbabwe, had argued that pushing Mugabe too hard could backfire.
It is not yet clear whether Zuma’s approach will be tougher than Mbeki’s. But in what was seen as a sign that Zuma was stepping up his intervention, he appointed two advisers and a special Zimbabwe envoy last week to work with politicians in Zimbabwe.
Zuma’s spokesman, Vincent Magwenya, said Sunday that leaders at a regional summit in early November had called on Zimbabwe’s politicians to start talks within 30 days to resolve their differences. Zimbabwean negotiators have been meeting behind closed doors in recent days, and Zuma’s team was to report back to him on their progress, Magwenya said.
"What is important is that parties are in dialogue and have to remain in dialogue in order to iron out all outstanding issues," Magwenya said.