Zimbabwe's new High Commissioner to South Africa praised this country as an "all weather friend" when he handed his letters of credence to President Jacob Zuma in Pretoria on Thursday.

"Your country, South Africa, has proved to be an all-weather friend to Zimbabwe and has refused to support the illegal sanctions imposed on Zimbabwe, and has instead demanded their immediate removal," Phelekezela Mphoko said at the presidential Guest House.

In 2002, the EU and US imposed sanctions on Mugabe and members of his government, not on the whole country.

Mphoko said he felt "greatly honoured" to stand in Zuma's presence.

The Democratic Alliance (DA) and Zimbabwe's opposition Movement for Democratic Change (MDC) party have criticised and expressed "dismay" at Zuma's decision.

President Robert Mugabe's appointment of Mphoko in July, along with envoys to the European Union, Switzerland and the United Nations, has irked his Prime Minister Morgan Tsvangirai.

EU countries said at the time they were concerned about the development, as they felt ambassadors should represent Zimbabwe's whole government, not just part of it.

Tsvangirai has claimed that according to the agreement reached when Zimbabwe's unity government was formed in January 2009, Mugabe should have consulted him about the appointments.

Tsvangirai previously asked South Africa and EU member countries to ignore the credentials of ambassadors who had been "unilaterally" appointed.

Accepting Mphoko's credentials, Zuma said he knew of Mphoko's "skills and capabilities".

DA spokesperson Kenneth Mubu said Zuma was undermining his administration's attempts to mediate peace in Zimbabwe by accepting the credentials.

"If the Global Political Agreement (GPA), brokered by South Africa, is going to work, then its terms must be respected by all political parties involved, especially the broker."

He said the terms of the GPA required Mugabe's Zanu-PF and the MDC to agree on all major appointments.

The MDC in South Africa said it was "dismayed" at Zuma's decision to accept the credentials.

"Robert Mugabe is not an executive president of Zimbabwe and cannot be allowed to behave as if it is business as usual. Mugabe is only a president by arrangement and not by winning elections," spokesperson Sibanengi Dube said.

Zuma was undermining his role as guarantor of the peace agreement reached between the MDC and Zanu-PF to form the unity government.

"Mugabe is compelled to seek Tsvangirai's endorsement before making any senior appointment. This requirement is in black and white," he said.

"By accepting Mugabe man's credentials Zuma missed an opportunity to display unquestionable leadership qualities."