Cabinet ministers will decide this morning whether all passengers arriving into Ireland should need to have a negative Covid test.
Public Health officials made the recommendation last night, after updating government party leaders on the Omicron variant.
The measures are expected to apply to all flights and ferries into Ireland, including from Great Britain.
New advice for children over-9 to wear masks in shops, at school, and while on public transport will also be considered by ministers at today's meeting.
Consultant in Infectious Diseases at Beaumont Hospital and Senior Lecturer at RCSI, Dr Eoghan DeBarra, says additional testing and travel restrictions will help delay the possible spread of the new variant.
"Any test informs us more about the epidemiology, and what variants may be around.
"What we're looking to do with these strategies is to get information and to buy time, so that we understand more the impact that Omicron might have.
"Ultimately any of the travel bans or other measures only potentially delay the entrant of a variant, we know that they still move and get in."
