Zimbabwe neighbours' aid campaign
Southern African countries are launching an urgent campaign to help Zimbabwe fight cholera and overcome its acute food shortage.
The plan was announced by President Kgalema Motlanthe of South Africa after a meeting in Pretoria of the Southern African Development Community (Sadc).
President Motlanthe also said he hoped a unity government would be formed in Zimbabwe in the coming days.
But Zimbabwe's opposition said it did not know what he was talking about.
After disputed presidential elections in March and June, President Robert Mugabe's Zanu-PF party and the opposition Movement for Democratic Change (MDC) agreed to form a power-sharing government.
But implementation of that deal, reached in September, has been deadlocked over whose supporters would get key ministries.
Meanwhile, 18,000 Zimbabweans have been infected with cholera and nearly 1,000 have died from the disease. Aid agencies warn cases will surge with heavy rains.
President Motlanthe said on Wednesday the Sadc appeal was being launched "for the people of Zimbabwe in order to help them overcome the challenges facing their country".
All 15 members of the regional body were expected to contribute to the aid effort, he added.
Correspondents say the Sadc campaign is firstly an international appeal to mobilise funds and resources for Zimbabwe's people.
It will also seek to address donors' concerns about food distribution being used by Mr Mugabe's government as a political tool.
'Tragedy'
The campaign was launched as Australia added its voice to growing calls for Mr Mugabe to stand down and tightened sanctions against his government.
Canberra added 75 individuals and four firms in Zimbabwe to a blacklist of financial and visa restrictions.
Foreign Minister Stephen Smith said the measures were "a clear signal the Australian government holds the brutal Mugabe regime and its closest supporters accountable for the tragedy occurring in Zimbabwe".
African countries like Botswana and Kenya have also urged Mr Mugabe to quit.
But in South Africa's capital, President Motlanthe told journalists he would not join calls for Mr Mugabe to step down.
He said: "The issue of whether President Mugabe should go or not was never been raised by the parties. So, it's really not for us - I mean, I don't know whether the British feel qualified to impose that on the people of Zimbabwe."
President Motlanthe said he hoped a constitutional amendment paving the way for power-sharing - with Mr Mugabe remaining president and MDC leader Morgan Tsvangirai becoming prime minster - would become law this week.
"We are hopeful that such an inclusive government will be put in place this week," he said.
'News to us'
But Zimbabwe's opposition said it knew nothing about any such breakthrough.
"We are not aware of any plans to form a government this week. It's certainly news to us because the outstanding issues we have outlined remain," MDC spokesman Nelson Chamisa told Reuters new agency.
The BBC's Jonah Fisher in Pretoria says the prospect of power-sharing still seems remote - in the week when Zimbabwe's government accused Botswana of hosting military training camps for MDC insurgents.
Meanwhile Nigeria's Foreign Minister Ojo Maduekwe told the BBC's HardTalk programme that while Nigeria shared the "moral outrage" about Zimbabwe, the best way to move forward was the power-sharing talks.
Earlier, the UK think tank International Crisis Group suggested that both Mr Mugabe and Mr Tsvangirai should step aside to end the "hopelessly deadlocked" talks.
This could allow a transitional administration to implement political and economic reforms, it said.
But BBC Africa analyst Martin Plaut says it is unlikely either side would take up such an idea.