Leaders of a Southern African bloc gathered on Monday in Zimbabwe to press President Robert Mugabe and the main opposition leader to break an impasse on forming a unity government.

Mugabe's lead negotiator Patrick Chinamasa told state media that he was "cautiously optimistic" of reaching a deal with rival Morgan Tsvangirai on how to share control of powerful ministries under the unity accord.

Chinamasa told the government mouthpiece Herald newspaper that the meeting "will end the saga over the allocation of ministries to bring finality one way or another, so that the country can move forward."

The security organ of the Southern African Development Community (Sadc) organised the summit in Harare after Tsvangirai boycotted talks one week ago in Swaziland, to protest delays in receiving his travel papers from Mugabe's government.

Just six weeks ago, regional leaders had come to Harare to celebrate the signing of the power-sharing deal, which calls for 84-year-old Mugabe to remain as president while Tsvangirai becomes prime minister.

The agreement had been hailed as an end to months of deadly political turmoil and a step toward piecing together Zimbabwe's shattered economy, which is saddled with the world's highest inflation rate at 231 million percent.

But Mugabe and Tsvangirai have failed to agree on which party should control the most important ministries, particularly home affairs, which oversees the police force.

South African President Kgalema Motlanthe, Mozambican President Armando Emilio Guebuza, Swaziland Prime Minister Barnabas Dlamini and Angolan foreign minister Assuncao dos Anjos hope to pressure the two sides into an agreement Monday to salvage the deal.

Former South African president Thabo Mbeki, who brokered the original agreement, said he was "very optimistic" going into the talks.

"Progress on the talks is very good," Mbeki told reporters as he arrived in Harare. Arthur Mutambara, leader of a faction of the opposition Movement for Democratic Change (MDC), said he expected the regional bloc to find a way to resolve the differences over the cabinet posts.

"The options are limited. We must make sure the 15 September agreement works," he told reporters.

"There is no way Mugabe will go it alone, and Mutambara and Tsvangirai can't walk away," he said.

The summit "is going to come out with a decision. None of us must go against Sadc," Mutambara added.

Tsvangirai defeated Mugabe in a first-round presidential vote in March, when the MDC also forced the long-ruling Zanu-PF into the minority in parliament for the first time.

But he failed to win enough votes for an outright victory and then pulled out of the run-off in June, accusing the regime of coordinating a brutal campaign of violence that left more than 100 of his supporters dead.

The protracted political feuding has dimmed the hopes of ordinary Zimbabweans, who had believed the unity government would lift the country's economic fortunes.

Zimbabwe's agriculture-based economy has been in free fall for nearly a decade, since Mugabe's government began seizing white-owned farms in a chaotic land reform scheme that gave land to poor blacks who often lacked the training for large-scale commercial farming.

Once seen as an African success story, Zimbabwe is now one of its failures with more than 80 percent of its population plunged into poverty, while the breakdown of infrastructure has led to chronic outbreaks of cholera and other diseases.

AFP