Chief Medical Officer Dr Tony Holohan is appealing to people with foreign holidays planned for this summer to cancel their flight and hotel bookings.
It comes as the National Public Health Emergency Team said it was noticing a "worrying trend" of COVID-19 cases increasing here, and new clusters emerging.
No new deaths linked to the virus were reported last evening - but 24 more cases have been confirmed, bringing the total to 25,462.
At least six of the cases reported yesterday were associated with international travel.
There has been one travel-related cluster in the north-west of the country, linked with travel to Iraq.
Dr Holohan is calling on people with summer holidays planned to reconsider.
Speaking yesterday evening, he said: "We would like people not to travel.
"Some people will have made bookings, and I think it makes much more sense to not go ahead with that booking than to risk travelling abroad and picking up this infection.
"The risks [are] for you, for any family members who are travelling with you, or indeed any close contacts you would have when you come back... and then the risk that represents for us as a community and society."
Dr Holohan noted it's not just in people's individual interests, but in the collective interest.
He said the message for anyone who "might perceive the infection represents less of a risk for themselves" is to think of other people.
He also noted that many typical summer holiday destinations are "having ongoing challenges" with coronavirus, leading to health officials being "genuinely very concerned" about the risk of the virus being re-imported.
Meanwhile, the Housing Minister has denied there's a split in opinion on foreign travel between Government and Dr Holohan.
It comes as the Government is drawing up a 'green list' of countries that the public can fly to without having to quarantine when they return.
Minister Darragh O'Brien said the Government respects the CMO's opinion.
He told Newstalk Breakfast: "In fairness, everyone respects the job that the medical profession are doing and the Chief Medical Officer has been doing."
He said the plans will become a 'little bit clearer' in the coming days.