Carter, Annan and rights activist Graca Machel – the wife of Nelson Mandela – planned to visit Zimbabwe at the weekend to find ways of easing a humanitarian crisis that has left half its population in need of emergency food aid.
President Robert Mugabe’s regime turned away the three, who belong to a group of senior statesmen known as the Elders, accusing them of seeking to bolster the opposition in power-sharing talks due to resume on Tuesday in South Africa.
"The so-called ‘Elders’ are a creature of pro-Labour British corporate interests. There is nothing elderly about them," Zimbabwe’s secretary for information George Charamba said in the government mouthpiece Herald newspaper.
"The ‘Elders’ should not pretend to have Zimbabweans at heart when, in fact, they were fronting a regime change agenda being pushed by Britain and the US," the paper said.
The Herald also accused the statesmen of trying to pave the way for United Nations intervention in Zimbabwe.
Negotiators for Mugabe and opposition leader Morgan Tsvangirai are due to attempt the latest bid to rescue a power-sharing deal signed more than two months ago but never put into effect.
Annan, Carter and Machel spent the weekend meeting with Zimbabwean exiles in South Africa.
Carter said on Monday that the humanitarian crisis was greater than feared, as a cholera epidemic is killing hundreds across the country.
"The entire basic structure… is broken down. These are all indications that the crisis in Zimbabwe is much greater, much worse than we ever could have imagined," Carter told reporters. – AFP