South Africa's government has imposed travel restrictions after confirming 61 cases of the novel coronavirus on Sunday.
The strict travel bans on foreign nationals from high-risk countries, including Italy, Iran, South Korea, Spain, Germany, the US, the UK and China — are effective from Wednesday.
"We have cancelled visas and previously granted visas are revoked," President Ramaphosa said on Sunday night.
He announced several other measures including the closure of schools from Wednesday, banning of all gatherings of more than 100 people in an effort to curb the spread of the coronavirus.
Schools will be closed from Wednesday March 18 and will remain closed "until after the Easter weekend".
The South African leader told the nation that the number of coronavirus cases was "expected to rise in the coming days and weeks".
"Initially it was people who have travelled outside the country, especially Italy. It is concerning now that we are dealing with internal transmission of the virus," he said.
Next week's Human Rights Day celebrations, a massive event on the South African calendar, has also been put off.
President Ramaphosa also encouraged South Africans to refrain from travel to high-risk countries, and said that non-essential domestic travel, particularly via plane, train and taxi, was discouraged.
"Never before in the history of our democracy has our country been confronted with such a severe situation," he said.
He added that government had declared COVID-19 a national state of disaster in terms of the Disaster Management Act.
"This will enable us to have an integrated and co-ordinated disaster management mechanism that will focus on preventing and reducing the outbreak of this virus. We will also be able to set up emergency rapid and effective response systems to mitigate the severity of its impact," he explained.