The Government is considering tighter restrictions on people coming in to Ireland from Britain to combat the spread of the Delta Covid variant.
It is understood the Government is looking at extending the period of quarantine for those arriving from Britain from five to 10 days if they are not vaccinated.
Minister for Foreign Affairs Simon Coveney earlier said a longer quarantine period for unvaccinated passengers could potentially be among the measures taken.
The Delta variant, which was first identified in India, is now the dominant strain in the UK.
It is proving to be 60% more transmissible than the previously dominant Alpha strain, which was first seen in Kent.
Speaking on RTÉ's This Week, Mr Coveney said: "The numbers are concerning and we need to do what we can within reason to do what we can to protect people here."
He said: "I don't want to announce anything today but we are looking at this seriously."
"Potentially longer quarantine periods particularly for people who aren't vaccinated," he added.
The minister said they need to slow down the spread of the variant in Ireland.
Mr Coveney said he spoke to Minister for Health Stephen Donnelly yesterday, saying "we want to get the balance right to protect the Common Travel Area as best we can".
Minister for Transport Eamon Ryan spoke to his counterpart in the UK yesterday, and Minister Ryan and Minister Donnelly were both in touch with Chief Medical Officer Dr Tony Holohan about concerns over the Delta variant.
Minister for Public Expenditure Michael McGrath said excellent progress is being made with the vaccination programme and the last thing Government wants to do is go backwards.
He said the Government is actively considering increasing the number of days unvaccinated people arriving here from Britain would have to spend in quarantine.
Currently, people arriving here from Britain have to quarantine at home but they can exit that after five days if they get a second negative PCR test.
There is a view in Government here that every week the Delta variant can be largely kept out of the State will boost the vaccination programme.
Solidarity-PBP TD Paul Murphy called on Government to go further and introduce mandatory hotel quarantine for those travelling here from Britain.
He said it was a race against time between the Delta variant and getting people fully vaccinated.
The TD said this race would be lost unless mandatory hotel quarantine is used for arrivals from Britain.
Such a measure would only need to be in place for a relatively short period, he said.
In Northern Ireland, the Public Health Agency said last week that 111 probable and confirmed cases of the Delta variant have been detected throughout all 11 local council areas, 28 of them in Kilkeel in Co Down.
In England, cabinet ministers are meeting this evening to decide whether or not to lift all coronavirus restrictions by 21 June.
It is reported that because of concerns about the Delta variant a delay of up to four weeks is being considered.
An announcement is expected to be made tomorrow.
