Passengers arriving into the Republic of Ireland from 16 additional countries are now subject to mandatory hotel quarantine with limited exemptions.
As of 4am this morning the list of Category 2 countries includes the United States, Canada, France, Belgium, Turkey and Italy.
The Department of Health has said that only people who had already pre-booked quarantine rooms should be allowed on these flights.
All passengers coming from the 16 additional countries will be required to check into designated hotels for up to 12 nights at a cost of almost €2,000 per person. Latest coronavirus stories Minister for Health Stephen Donnelly said the decision was made "following public health advice relating to variants of concern with Covid-19".