President Cyril Ramaphosa has declared a national state of disaster as the number of confirmed Covid-19 cases increased from 51 to 61 on Sunday. Ramaphosa also announced several response measures to limit the spread of the novel coronavirus, which has been declared a pandemic by the World Health Organisation.READ | Covid-19 has been declared a national disaster in SA – here’s what that meansThe president, addressing the nation after a special Cabinet meeting, added that it was expected that the number of cases would increase in the coming days.The number of positive cases has been growing at an increasing rate since the first one was announced on Thursday 5 March.The measures announced by the president include a ban on public gatherings of more than 100 people, and a travel ban for foreign nationals from severely affected countries - Italy, Iraq, South Korea, Spain, Germany, United States, United Kingdom and China - from 18 March 2020. The visas of those travelling from the severely affected countries will be cancelled and revoked. Ramaphosa also discouraged South Africans from travelling to affected countries in the European Union, United States, United Kingdom, China and South Korea. He said the newly confirmed cases of internal transmissions was concerning to government, adding that it called for an "extraordinary response". Until Sunday, all of the people who tested positive were citizens who had travelled to countries which had recorded cases of the virus. "We have decided to declare a state of disaster in terms of the Disaster Management Act. This will enable us to have an integrated and coordinated 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," Ramaphosa said. South Africans who are returning from affected countries will also face intensive screening and possible quarantine, with government promising to strengthen surveillance and screening at King Shaka, OR Tambo and Cape Town international airports. Ramaphosa said 35 land ports would be shut down from Monday, with two of the eight seaports closed for passenger and crew changes. "Effective immediately, all non-essential travel for all spheres of government outside of the Republic is prohibited. We further discourage all non-essential domestic travel, particularly by air, rail, taxis and bus. Secondly, it is essential therefore that we minimise the risk of the spread of this virus by limiting contact amongst groups of people. While we appreciate the economic, religious, and cultural significance of social and community gatherings, the coronavirus is spread through contact between persons.Thuma Mina moment"As we have said before, the current circumstances require extraordinary measures to curb the spread of infections. Countries that have heeded the call to implement these radical measures, have fared much better than those than do not.Therefore to encourage social distancing ."The president also announced that schools would be closed from Wednesday and would remain closed until after the Easter weekend.To compensate, the mid-year school holidays would be shortened by a week, he added. "We are in process of identifying isolation and quarantine sites in each district and metro. Capacity is being increased at designated hospitals in all provinces. We are also increasing the capacity of existing contact tracing processes. "We are partnering with the private sector to set up a national tracking,tracing and monitoring system of all people infected with the coronavirus and those they have been in contact with. We are undertaking a mass communication campaign on good hygiene and effective prevention behaviour," he said. Encouraged that the country could win the fight against the scourge of Covid-19, Ramaphosa said it was the most definitive Thuma Mina moment for the country thus far. He said if South Africans acted swiftly, with purpose, and collectively, the country could "overcome it"."Although we may be limiting physical contact, this epidemic has the potential to bring us closer together.We are responding as a united nation to a common threat. This national emergency demands cooperation, collaboration and common action. More than that, it requires solidarity, understanding and compassion. Those who have resources, those who are healthy, need to assist those who are in need and who are vulnerable."