Taoiseach Micheál Martin has said that any spike in coronavirus cases is of concern.
He said the Government will “watch and monitor very carefully” what happens with the number of Covid-19 cases in the coming days.
It came as health chiefs in the Republic said that 85 new cases reported on Thursday were a worrying escalation.
A factory in Kildare and at least two direct provision centres in the Midlands, where some of the workers live, have created a cluster of infection.
Construction sites are also linked to the sudden increase, health officials said.
Speaking at Dublin Castle before the start of the North South Ministerial Council (NSMC), Mr Martin said: “Obviously any spike at all we are concerned about.
“We have to watch and monitor very carefully what happens now over the next number of days in terms of whether that is a pattern or whether it’s relating to specific clusters that have emerged in recent days.
“What is heartening is the response of the testing and contact tracing apparatus now within the Republic.”
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• difficulty breathing
• loss or change in taste or smell#ProtectEachOther #StaySafe pic.twitter.com/N9NZzIrwhj
He said he spoke to Dr Ronan Glynn on Thursday evening and that the acting chief medical officer is “quite intensive” in getting on top of testing and contact tracing.
Dr Glynn said: “We are very concerned.
“I hope this is a blip, I hope we see a much smaller number of cases tomorrow.”
He added that the factory in Co Kildare has seen 30 to 40 positive cases but not all tests have been returned yet.
A total of 18 of Thursday’s tally were associated with the factory.
“We need to watch this extremely closely, we need to see in particular what happens tomorrow and the next day,” Dr Glynn said.
“We do understand where the vast majority of these cases have come from.
“The question now is what happens next.”
One more death was reported on Thursday by the National Public Health Emergency Team.