The Health Minister says it's still too early to say whether the next stage of reopening can go ahead as planned.
Stephen Donnelly said the Government needs to hear from NPHET next week, amid "significant" concern about the Delta variant.
He said the situation with the variant is "rapidly evolving".
The next stage of reopening - which includes the return of indoor dining in pubs and restaurants - is due to take place on July 5th.
Tánaiste Leo Varadkar yesterday said things were still on track for the next easing of restrictions.
However, Minister Donnelly told Newstalk Breakfast they need to hear from NPHET first before pushing ahead with the plans.
He said: “The public health team are watching the Delta variant very, very closely - and we’ll see what the data says next week.
“Just last Thursday, I was talking to the team last week after NPHET and it was believed the Delta variant was about 5% of new cases. In fact, the data we saw from whole genome sequencing was that the number of new cases of Delta variant was actually falling week on week.
“But new information that's come in the last few days… shows it could be up to 20% of cases. It’s a rapidly evolving situation.
“What we need to do is what we always do - let the scientists and public health doctors do their thing, and let them pore over the analysis."
He said officials will be meeting "through next week" ahead of the final decision on pushing ahead with the next stage of reopening.
The Health Minister described the Delta variant is “a very significant problem” - noting it's now linked to 90% of COVID-19 cases in Britain, and growing “very quickly” in Europe and Northern Ireland.
He said: “We’re watching the UK very closely, and the exact numbers are moving around. But what we know about the Delta variant is it seems to be a lot more contagious… seems to be significantly more severe in terms of the risk of being hospitalised… and appears to be less susceptible to vaccines, certainly in terms of having just one vaccine dose.
“What the experts tell me is that variants like this - which are so much more contagious - inevitably become dominant.
“The question for us is what needs to be done to make sure as many people as possible are fully vaccinated."