An extra 13 countries have been added to the list of 'high-risk' countries.
Health Minister Stephen Donnelly says passengers arriving from these countries must comply with a mandatory 14-day period of self-quarantine.
20 states were already on the list, so the total has now come to 33.
The newly added countries are Argentina, Bolivia, Chile, Colombia, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Suriname, Uruguay and Venezuela.
Anyone arriving from those countries must self-quarantine for the full two weeks, even if they get a negative PCR test.
Once the necessary legislation is passed in the coming weeks, the mandatory quarantine will be in designated hotels.
Minister Donnelly said: "If you travel to Ireland from any of the high-risk countries, you must complete a full 14-day quarantine period.
“This applies to all passengers from designated states, regardless of nationality and the aim of this measure is to protect the population from challenges posed by new variants of concern.”
The current list of 33 'high-risk' countries is: Angola, Argentina, Austria, Bolivia, Botswana, Brazil, Burundi, Cape Verde, Chile, Colombia, Democratic Republic of the Congo, Ecuador, Eswatini, French Guiana, Guyana, Lesotho, Malawi, Mauritius, Mozambique, Namibia, Panama, Paraguay, Peru, Republic of South Africa, Rwanda, Seychelles, Suriname, Tanzania, United Arab Emirates, Uruguay, Venezuela, Zambia and Zimbabwe.