DUBLIN, Jan 26 (Reuters) - Ireland is to introduce a 14-day quarantine in hotels for all people arriving from Brazil and South Africa, and for anyone arriving without evidence of a negative coronavirus test, the government said on Tuesday. Visa-free travel from both countries and from all of South America has been suspended until March 5, Prime Minister Micheal Martin said. Ministers signed off on the measures, which are aimed at stopping more transmissible variants entering Ireland, while extending a national lockdown until March 5. The quarantine period - 14 days - was announced later at a news conference. Deputy Prime Minister Leo Varadkar said on Monday that any easing of restrictions, when they eventually come, will be very slow. COVID-19 cases have begun to fall sharply since rising at the fastest rate in Europe at the start of the year, following a four-week relaxation of restrictions and increased prevalence of the more transmissible variant first detected in England. Ireland reported three cases of the South African variant earlier this month, which health officials said had been contained. No cases of the Brazilian variant have been discovered. The government has said it will take a few weeks to put the system in place. Under previously announced measures, anyone flying into Ireland must show they have had a negative/not detected COVID-19 test from the previous 72 hours. Varadkar also said that although the government was not ruling out extending hotel quarantine to all arrivals, as demanded by most opposition politicians, it would not be fully effective because of different rules across the open border in British-run Northern Ireland. It would also create issues around supply chains, he added. Britain was due to announce later on Tuesday whether it will bring in mandatory quarantine in hotels for some or all arrivals. (Reporting by Padraic Halpin and Conor Humphries, Editing by Timothy Heritage)