The US will not be on Ireland's green list for safe travel and the UK is also very unlikely to be included, the country's foreign minister has said.
Simon Coveney said the list, which is due to be published on Monday, will not be particularly long.
Currently people arriving in Ireland from overseas - with limited exceptions such as essential supply chain workers - are required to fill in a passenger locator form and self-quarantine for 14 days.
People crossing the border from Northern Ireland are not subject to restrictions on their movement.
Travellers arriving in Ireland from countries on the new green list will not be required to isolate for two weeks.
People can still enter Ireland from countries not on the green list, but they will be required to self-isolate.
The Irish Government continues to advise citizens not to travel abroad for holidays this summer.
However, people who do choose to visit countries on the green list will not be required to quarantine themselves on their return.
Mr Coveney said Cabinet decisions on which countries would be included on the list will be based on science and epidemiological data and not politics.
He said countries will be excluded from the green list if their Covid-19 infection rates exceed a set threshold.
"I think there's no question that the US will be on the green list, it won't be," he told the Pat Kenny Show on Newstalk.
"And I think it's very unlikely our closest neighbour either will be under that threshold that we set.
"And that's really unfortunate because the two countries that we would like to be opening up to, in terms of international travel, are the UK and the US, given the integration between our economy of those two countries and of course the number of visitors that would like to come here to spend money in hotels and have holidays here and so on.
"So, I think it's very unlikely that either the UK or the US will be on that green list.
"It's not going to be a particularly long list.