Ireland is imposing new limits on people arriving into the country from Denmark because of the mutation of COVID-19 in minks there.
Everyone arriving from there will have to quarantine for the full 14 days, even if they are essential travellers like doctors, truck drivers, diplomats and seafarers.
It comes as further steps are taken to bring Ireland into line with the EU traffic light system for travel during the pandemic.
From midnight on Sunday, Ireland's colour-coded risk categorisation now refers to EU regions, rather than individual countries.
Meanwhile, a 14-day isolation period for travellers arriving from Denmark into Northern Ireland has also been announced by the Stormont Executive.
The rules, effective from 4am on Saturday, apply to anyone who has arrived back from Denmark into any part of the UK, including Northern Ireland, since October 23rd.
All members of the household are also required to isolate.
The UK is banning foreign visitors arriving from Denmark after widespread outbreaks of coronavirus in the country's mink farms.
British nationals or residents who are returning to the UK from the nation are now required to self-isolate for two weeks.
Danish farms have been ordered to cull millions of the animals, which are kept in tightly packed cages and bred for their fur.
There are no direct flights between Northern Ireland and Denmark, rather people would have to travel through Britain or Dublin.
Additionally, there are no mink farms in the North while there are three in the Republic.
Northern Ireland's Health Minister Robin Swann has been in contact with Stephen Donnelly about the issue.
The Northern Ireland Executive said the rules are "precautionary measures" after health authorities in Denmark reported "widespread outbreaks of coronavirus in mink farms, with a variant strain of the virus spreading to some local communities".
Northern Ireland’s Chief Medical Officer Dr Michael McBride said: “Self-isolation for anyone who has been in Denmark is a mandatory requirement and it applies to all members of the household.
“This is an emerging picture and a precautionary approach is required at this early stage.
“We are in very close contact with public health colleagues in Great Britain and the Republic of Ireland. Minister Swann has also been in contact with his Republic of Ireland counterpart Stephen Donnelly.
“Advice and guidance have been issued to health service colleagues in Northern Ireland.
“The UK authorities are working closely with international partners to understand the changes in the virus that have been reported in Denmark. A programme of further research in the UK will inform risk assessments.”