JOHANNESBURG (AP) -- South African President Jacob Zuma heads to neighboring Zimbabwe on Tuesday, marking his first official trip as chief mediator between the president and prime minister in Zimbabwe's troubled coalition government.
On a crucial two-day trip, Zuma will make an assessment of the coalition agreement a year after the government was sworn in, his office said in a statement. He also will examine how regional mediators can "fast-track" the removal of obstacles holding back full implementation of the country's unity deal.
Zuma will meet with President Robert Mugabe and longtime political rival Morgan Tsvangirai, now prime minister, over a series of disputes between their two parties that have weakened the coalition and also led to Tsvangirai's three-week withdrawal from it in November.
Zuma, who helped save the government from total collapse in November, replaced former South African President Thabo Mbeki as the chief mediator appointed by the Southern African Development Community, a 14-nation regional economic and political bloc.
Critics accused Mbeki of not doing enough to force the coalition partners to observe provisions of the unity deal and hope Zuma will take a firmer stand on his first trip.
Tsvangirai's Movement for Democratic Change party blames Mugabe for reneging on key provisions of the deal that allow for democratic and media reform, and an end to lawlessness after years of political and economic turmoil.
Mugabe alleges Tsvangirai's party failed to win concessions from its Western allies to remove targeted sanctions against his loyalists.
Last week, Mugabe stripped four ministers of the former opposition of some of their powers, handing over those responsibilities to ministers from his own party. Tsvangirai protested the changes and declared them null and void but they were not rescinded by Mugabe.
The prime minister also expressed dismay over sweeping plans under an act passed by Mugabe's lawmakers before disputed elections in 2008 to give black "indigenous" Zimbabweans a majority stake in private businesses.
Those laws, which became effective March 1, will affect South African-owned businesses, mines and farms and already have put on hold proposed foreign investments.
The coalition agreement calls for fresh elections next year under a new constitution, but efforts to rewrite the constitution are largely stalled through bickering and funding shortages.
A defiant Mugabe earlier this month declared he could call elections "with or without a new constitution."
Also in dispute with Tsvangirai are top government appointments and the sharing of 10 powerful provincial governorship posts. None has gone to Tsvangirai's nominees.
In December, Zuma sent a team of "facilitators" to work with Zimbabwean political leaders on the obstacles to power-sharing in Zimbabwe. None of their findings has been released after Mugabe's party insisted such negotiations could not be conducted in public.