President Jacob Zuma says he is "greatly concerned" at the political turmoil in Zimbabwe and says he hopes it would not lead to unconstitutional changes in government.
Zuma, who is the current chairperson of Southern African Development Community (SADC), called for "calm and restraint" in a statement on behalf of SADC.
"[He] has expressed hope that developments in Zimbabwe would not lead to unconstitutional changes of Government as that would be contrary to both SADC and African Union positions", the statement continued.
"The President has urged the Government of the Republic of Zimbabwe and the Zimbabwe Defence Force to resolve the political impasse amicably and has urged the Zimbabwean Defence Force to ensure that the maintenance of peace and security in the country is not compromised."
SADC would closely monitor the situation and remain ready to assist where necessary to resolve the political impasse in keeping with established SADC protocols, the statement continued.
Zuma said he has decided to deploy a special envoy to Zimbabwe in light of the developments regarding President Robert Mugabe.
The envoy, which will start in Angola, will be led by Defence Minister Nosiviwe Mapisa-Nqakula and State Security Minister Bongani Bongo.
"The Special Envoys will also be sent to the Republic of Angola to see President Joao Lourenco, Chairperson of the SADC Organ on Politics, Defence and Security to brief him on the situation," the Presidency said in a statement.
This comes as President Robert Mugabe is said to be under heavy guard after soldiers cordoned off the parliament building and the defence headquarters, as the security situation deteriorates in the southern African country.
South Africa is willing to act as a mediator in Zimbabwe's political crisis, Clayson Monyela, spokesperson for the Department of International Relations (Dirco), has said.
Monyela told Radio 702: "Zimbabwe is where it is today because South Africa has consistently and regularly been part of the mediation process over the past years. So we are interested in what is going on... in the nation."
He continued: "South Africa is willing to be a mediator, we have done it before and based on the briefing we will decide the way forward."