Granting Zimbabwean first lady Grace Mugabe diplomatic immunity was painful, International Relations Minister Maite Nkoana-Mashabane said on Wednesday.

"I am here. My name is Maite Nkoana-Mashabane. [I am] a very responsible mother, you can ask my children. Others know I am very supportive. It’s been a very painful exercise. It still is. Having said that, we are following the law," she told reporters in Pretoria.

She said she had written to National Assembly Speaker Baleka Mbete and the chair of Parliament’s international relations portfolio committee, Siphosezwe Masango, to report on the matter.

"We have written to Parliament and we will follow up on this matter."

Mugabe was allowed to leave the country with her husband Robert on Sunday, despite being accused of assaulting model Gabriella Engels, 20, in a Sandton hotel the previous weekend. Engels had visited her two sons at the time.

On Sierra Leone

Nkoana-Mashabane said South Africa would not send a humanitarian response team to Sierra Leone, where a mudslide killed hundreds of people on the outskirts of the capital Freetown on August 14. Hundreds are still missing.

"Instead, we are announcing an initial contribution of R8-million through the United Nations World Food Programme."

She called on South Africans to contribute to the relief effort by making donations to the South African Red Cross.

Nkoana-Mashabane said the disaster in Sierra Leone was just another demonstration of the urgent need to address climate change. Climate change was no longer about "which God we believe in. It’s real".

She said Africans were appealing to all leaders to make resources available to ensure countries could adapt to climate change.

"We are not making these pleas in vain or in ignorance. We know that it is no longer a story of Noah and the ark. It’s real and it’s happening now."