Zuma made his toughest comments yet on the delay in issuing election results in Zimbabwe as members of the U.N. Security Council and the African Union met in New York where they were expected to debate Zimbabwe, Sudan and Somalia.

Mbeki, increasingly isolated in his softly softly approach to Zimbabwe and his insistence there is no crisis there, is chairing the meeting at U.N. headquarters as rotating Security Council president. He wants to block discussion of Zimbabwe.

Zuma said in a speech near Johannesburg: "The region cannot afford a deepening crisis in Zimbabwe. The situation is more worrying now given the reported violence that has erupted."

Zuma ousted Mbeki as leader of the African National Congress last December and has moved gradually to increase his influence at the expense of his rival.

"We once again register our apprehension about the situation in Zimbabwe. The delay in the verification process and the release of results increases anxiety each day," Zuma told South Africa's Chambers of Commerce.

A judge in Harare on Wednesday adjourned until Thursday hearing an MDC application to block a recount of all votes cast in 23 out of 210 constituencies in the March 29 parliamentary and presidential elections.

The MDC says the recount is another tactic by Mugabe to delay the election results while he orchestrates a campaign of militia violence to intimidate opposition supporters.

The High Court has already refused to order the Zimbabwe Electoral Commission to release the presidential result.

FIRST DEFEAT

The MDC, which handed Mugabe's ZANU-PF party its first defeat in the parliamentary poll, says Tsvangirai should be declared leader of the economically devastated country after winning the undeclared presidential poll.

ZANU-PF says Tsvangirai did not win an absolute majority and a runoff will be necessary.

U.N. Secretary-General Ban Ki-moon joined the United States, Britain and France in urging the New York meeting to discuss Zimbabwe.

The meeting will also be attended by British Prime Minister Gordon Brown. London also accuses Mugabe of delaying the election result to try to subvert the outcome.

The MDC and human rights groups say independence war veterans and other pro-Mugabe militia have organised systematic violence to try to ensure victory in a probable runoff.

An NGO called Zimbabwe Doctors for Human Rights said on Wednesday it had treated 173 victims of organised violence and torture between March 29 and April 14. It did not say who the victims or perpetrators were.

A summit of southern African nations in Zambia last weekend called for the rapid release of the election results but did not use the word crisis -- apparently at the insistence of Mbeki, who leads the region's biggest power.

A general strike called by the MDC on Tuesday to push for release of the presidential result flopped, with most workers deterred by the fear of a police crackdown and their inability to make ends meet without working.

Zimbabwe is suffering the world's highest rate of hyper-inflation, at more than 100,000 percent, chronic shortages of food and fuel and 80 percent unemployment.

South Africa and other countries in the region have been flooded with millions of Zimbabwean economic migrants as a quarter of the population fled.