President Ramaphosa has decided that the country must, "Urgently and dramatically escalate the response to the Covid-19 challenge".
"We have learnt that those countries who acted swiftly and dramtically were successful."
There will be a nationwide lockdown from midnight Thursday for 21 days.
From midnight Thursday until 16th April all South Africans will have to stay at home. Those exempted are - health workers, emergency personnel, security services, those involed in food, banking, power, water, telecommunications, medical, hygiene, and some others.
Individuals will not be allowed to leave their homes except to seek medical care, buy food, medicine or collect a social grant. Temporary shelters will be prepared for the homeless.
All shops and businesses will be closed except for pharmacies, banks, petrol stations, medical suppliers and some others that will be exempted.
"The nationwide lockdown is necessary," said President Ramaphosa.
"It is clear from the development of the disease in other countries & from our own modelling that immediate, swift and extraordinary action is required if we are to prevent a human catastrophe of enormous proportions in our country," said Ramaphosa.
"We must therefore do everything within our means to reduce the overall number of infections and to delay the spread of infection over a longer period – what is known as flattening the curve of infections.
It is essential that every person in this country adheres strictly – and without exception – to the regulations that have already been put in place and to the measures that I am going to announce this evening.
Our analysis of the progress of the epidemic informs us that we need to urgently and dramatically escalate our response.
The next few days are crucial.
All shops and businesses will be closed, except for pharmacies, laboratories, banks, essential financial and payment services, including the JSE, supermarkets, petrol stations and health care providers" said the president.
The Presiden'ts speech came on the day which saw a significant jump in confirmed cased from 274 to 402. The biggest increase was recorded in Gauteng where confirmed cases increased by 75 from 132 to 207.
The country completed 3 500 tests in one day. Positive cases have now been recorded in all provinces of the country.