Tsvangirai, head of the Movement for Democratic Change, held a news conference in Johannesburg, South Africa, Voice of America reported. He said South African President Kgalema Motlanthe, who heads the Southern Africa Development Community, was arranging the meeting.
Zimbabwe has been in economic freefall for several years and its currency is now worthless. A cholera epidemic has killed at least 2,000 people and sickened thousands and has spread across its borders, threatening South Africa and other neighbors.
Tsvangirai said power sharing means making Zimbabwe's security forces subject to law and ending arrests and assaults on MDC supporters. He said there must be an equitable distribution of cabinet posts between MDC and the ruling Zanu-PF party.