Harare - Zimbabwe's President Robert Mugabe has described as "devastating" the removal from office of his South African counterpart Thabo Mbeki, who is seen as a key ally of the of ageing authoritarian Mugabe in the last eight years.

"It's devastating news that President Thabo Mbeki is no longer the president of South Africa," the Zimbabwe's state-controlled daily Herald newspaper quoted Mugabe as saying Thursday.

"But that is the action of the South African people," he added. "Who are we to judge them? But it is very disturbing."

Mugabe was speaking to journalists from Zimbabwe's state media in New York where he is due to address the United Nations general assembly.

South Africa's ruling African National Congress (ANC) party on Saturday demanded Mbeki resign, after a court ruling that he may have manipulated the prosecution of ANC president Jacob Zuma on charges of the fraud and corruption, to destroy the political career of his chief rival.

Mbeki's resignation came less than two weeks after he managed to bring together Mugabe and Zimbabwe's pro-democracy leader Morgan Tsvangirai to sign an agreement on power-sharing meant to end the decade of economic and humanitarian chaos.

However, Mbeki has been widely criticized for siding with Mugabe during the 18-month process of negotiations that he chaired as the mediator on behalf of the 14-member regional Southern African Development Community.

Critics say he has refused to criticize Mugabe for his violent repression of his opponents with his controversial policy of "quiet diplomacy."

Analysts warn that with Mbeki now out of the way, Mugabe faces a potentially hostile new hierarchy in South Africa that has been outspoken in its criticism of him and his role in Zimbabwe's economic collapse and its series of elections marked by violence and fraud.

The agreement between Mugabe and Tsvangirai, as well as a small faction of Tsvangirai's Movement for Democratic Change (MDC) party, stalled almost immediately after it was signed on September 15.

The three groups failed to agree on sharing ministries, with MDC officials saying Mugabe demanded he retain the key ministries of defence, home affairs - with includes the police - and finance.

Tanzanian president Jakaya Kikwete, speaking in New York on Wednesday, said there was "no cause for alarm" over the effect that Mbeki's resignation would have on the Zimbabwean initiative.

"The South African government remains and will continue to focus on the issue."

SADC spokesman Charles Mubita was quoted in the Herald as saying Mbeki would continue to be the mediator between Mugabe's Zanu-PF party and the MDC.

"It does not need someone to be a sitting president to facilitate in a dispute," he said. "It does not subtract anything because he has resigned, unless he thinks otherwise.

"Mbeki was appointed by SADC to facilitate mediation in Zimbabwe and this appointment was based on his knowledge, understanding and acumen of the situation. The status quo remains as it is," Mubita said. (dpa)