JOHANNESBURG — Zimbabwe must not return to instability, continental powerhouse South Africa said Wednesday after President Jacob Zuma held talks with Prime Minister Morgan Tsvangirai who has cut ties within his unity government.

Zuma met Tsvangirai after the Zimbabwean leader left Harare two days ago on a diplomatic mission to appeal for regional mediation in the stand-off with ruling partner President Robert Mugabe.

"Zimbabwe should not be allowed to slide back into instability," Zuma said after the two leaders met in Cape Town.

Tsvangirai flew back to South Africa after meeting Mozambican President Armando Guebuza on Tuesday and now heads to the Democratic Republic of Congo and Angola to brief leaders on the government's worst impasse in eight months.

Tsvangirai cut ties with Mugabe's "dishonest and unreliable" camp on Friday, saying he will call off the boycott once all outstanding issues are resolved, including disputes over posts and a crackdown against his supporters.

"President Zuma reiterated his government's readiness to assist in the full implementation of the unity pact underpinning Zimbabwe's power-sharing government," the South African presidency said in a statement.

"He expressed concern at the situation in Zimbabwe," it added.

The Southern African Development Community (SADC) body on politics, defence and security -- which is chaired by Mozambique's Guebuza -- will meet in Zimbabwe next week, Zuma's office said citing Tsvangirai.

The 15-member SADC bloc mediated Zimbabwe's protracted political crisis with a unity government sworn in nearly year after disputed polls that saw Mugabe re-awarded the presidency after a one-man run-off.

In Harare, Tsvangirai's Movement for Democratic Change (MDC) welcomed Zuma's comments after the party snubbed a business-as-usual cabinet meeting led by Mugabe on Tuesday.

"We welcome the comments and concerns raised by President Zuma as these are concerns shared by the majority of Zimbabweans," said MDC spokesman and cabinet member Nelson Chamisa told AFP.

"We cannot allow this process to slide back, that would be catastrophic, it's political suicide."

Tsvangirai travels to the DR Congo, whose President Joseph Kabila is current SADC chair, on Thursday and to Angola on Friday, he said.

Mozambique President Armando Guebuza's spokeswoman Marlene Magaia said Zimbabwe's three unity leaders -- Mugabe, Tsvangirai and smaller MDC faction head Arthur Mutambara -- will meet after the DR Congo visit.

"After he (Tsvangirai) meets with President Kabila who is currently SADC chairman on Friday, the three will meet in Zimbabwe," she told AFP in Maputo.

The unity government was set up in February, nearly a year after disputed polls which saw Mugabe handed the presidency after a one-man run-off following Tsvangirai's withdrawal after violence against his supporters.

The MDC leader said his withdrawal does not indicate that he has quit the government, with the suspension sparked by last week's renewed detention of top aide, Roy Bennett who was later released on bail, on terror charges.

By AFP