The Taoiseach has raised the prospect of further counties being placed under the same tightened coronavirus restrictions in force in Dublin.
Micheál Martin highlighted Louth, Donegal and Waterford as areas giving rise for concern.
He said experts on the National Public Health Emergency Team would be carefully considering whether to advise government that restrictions should be tightened in those counties.
Dublin is currently subject to Level 3 restrictions under the government's Covid-19 five-tier response plan, with the rest of the country at Level 2.
The stricter measures in place in the capital include a ban on indoor social gatherings; a requirement for pubs and restaurants to only serve food outdoors, while travel in and out of the county has been limited to work, education and essential purposes.
Mr Martin warned that other counties could soon move to Level 3.
His remarks came as pubs that do not serve food prepared to reopen, everywhere apart from Dublin, six months after thousands of publicans closed their doors.
"Nphet will advise us on a continuing basis in relation to the rest of the country," the Taoiseach told Newstalk.
"Certainly Louth, Donegal and Waterford are giving rise for concern, and the CMO (chief medical officer) has said this to us, Ronan Glynn, and obviously that will be closely monitored.
"It is a significant decision to move up to Level 3 for any county, so that would be carefully considered and obviously Nphet will advise government in relation to those counties and the broader situation."
Earlier today a public health expert urged people to reduce their social contacts to those who are a priority.
Professor Philip Nolan, chairman of the epidemiological modelling advisory group, warned every social interaction carries a risk and advised people, particularly those living in Dublin, to cut their social contacts by half.
Prof Nolan, a member of Nphet, said after 396 cases of Covid-19 were reported on Sunday: "I was a little bit taken aback when I opened the file yesterday afternoon to find that was the number so it's a warning to us, if a warning was needed, to treat this virus very seriously.
"I don't think we should panic or be excessively anxious when we see these numbers. It requires a calm response. We still can get this virus under control.
"We did expect numbers to continue to rise in the course of this week and would hope to see a change in the following week and the week after.
"It is a reminder to everyone to observe those basic measures and to reduce our social contacts to those that are a priority."
He added the dynamics of viral transmission is that "you go in quickly and reverse out slowly".
The Nphet member said if people in Dublin work hard to follow new restrictions, at best there will be a stabilisation or a downward trend in cases.
He added, if the average number of cases stabilises in 10 days, the restrictions are working.
Asked about the reopening of pubs, he said: "You can go to the pub outside Dublin, the question is should you and how often?
"It's not that we want people to have no social contact.
"Social contact is important for our welfare and mental health.
"For people's welfare we want them to on some level have social interaction but every social interaction carries a risk."
Read more:Social contacts should be cut by half, says public health expert
