The Southern African Development Community (SADC) has dismissed moves by President Robert Mugabe's party to push for a new mediator in the country's inter-party talks.
South African President Jacob Zuma has been the regional bloc's mediator in the Zimbabwe talks since 2009.
His facilitators have, however, repeatedly clashed with President Mugabe's Zanu PF party, which accuses them of taking sides in the dialogue meant to end the country's decade-old economic crisis.
On Tuesday, the state media quoted a Zanu PF official (name withheld) saying President Zuma must give up the mediation role when he assumes chairmanship of SADC's organ on politics, defence and security cooperation.
The South African leader will take over the new role at the SADC summit to be held in Angola beginning August 15. Mr Tomaz Salamao, the SADC executive secretary, said Mr Zuma's position was not up for discussion at the summit.
"The fact that he takes up a new position as the chairperson is not an issue at all," Mr Salamao told the Daily News newspaper on Tuesday. "SADC gave him a mandate and he will have to continue carrying out that mandate."
President Zuma took over from his predecessor Mr Thabo Mbeki who helped broker the power sharing agreement that led to the formation of Zimbabwe's unity government in 2009.
Mr Zuma is currently pushing for election reforms ahead of fresh polls that will be held next year. His no-nonsense approach has angered President Mugabe's supporters who want fresh elections held before the end of the year.
The spokesperson of Mr Zuma's facilitation team in Zimbabwe, Ms Lindiwe Zulu, said there was nothing wrong with the South African leader playing the roles of facilitator and chairing the SADC organ at the same time. "We have the capacity to handle both because there is a facilitation team to handle that," she said.
"The facilitation team will then report to Mr Zuma as the troika chairperson. President Mugabe in March accused Mr Zuma's team of dictating to Zimbabwe on the electoral reforms after SADC rebuked him for failing to stop political violence.