Chief Medical Officer Dr Tony Holohan is appealing to people with foreign holidays planned for the 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 a travel-related cluster in the north-west of the country, linked with travel to Iraq.
Dr Holohan is now 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.