The former United States president, Jimmy Carter, and former head of the United Nations, Kofi Annan, have met the Zimbabwean opposition leader in South Africa after being denied entry to Zimbabwe.
The two men met with Morgan Tsvangirai after they were refused entry because the government accused them of backing the opposition.
Mr Carter accused Harare of ignoring the hardships of its people as he, Mr Annan and Graca Machel - the wife of Nelson Mandela - were refused visas.
But the foreign ministry in Harare - which earlier said the visit was aimed at boosting the opposition in power-sharing talks - denied that it had barred the trio from entering.
"We've been told by a senior official here that they felt our presence may interfere with the political negotiations," Mr Annan told a joint press conference in Johannesburg.
"It is obvious the government is determined to prevent our entry in Zimbabwe," said Mr Carter, adding that President Robert Mugabe's regime was "immune to reaching out for help for their own people."
But in Harare, foreign ministry spokesman Simbarashe Mumbengegwi said: "The government of Zimbabwe has not barred Mr Annan and his team from coming to Zimbabwe."
The visit had only been postponed, he said because Annan had not consulted the government on its timing and program, "as is the normal practice."
He added: "It is most unfortunate that the former secretary general has, for reasons best known to himself, misrepresented the position of the government of Zimbabwe. We expect someone of his level to observe the correct procedure and practice."
Mr Mugabe and Mr Tsvangirai have yet to form a unity government, despite several failed attempts by regional leaders to force the implementation of a September 15 accord.
Mr Annan rejected accusations his delegation was partisan, stating that its mission was purely to assess Zimbabwe's humanitarian needs.
Kofi Annan, Jimmy Carter and Graca Machel, are part of a group of prominent figures and former statesmen called The Elders.
