Cities may be placed on higher restrictions than the rest of the county they're in, under new plans being considered by officials.
NPHET is examining whether Cork, Waterford, Limerick and Galway cities could be moved up a level on the COVID-19 restriction list, without doing the same for the entire county.
It comes as the spread of the virus continues to rise in urban areas.
Taoiseach Micheál Martin says they are looking at differentiating cities from counties.
He said: "NPHET will advise us in terms of any restrictions that may have to come in for other areas.
"They are concerned about urban centres... particularly as universities and institutes of technology reopen in the coming weeks."
"NPHET may advise in terms of particular localised restrictions... to date it's been on a county-by county basis.
"The numbers are growing in the city and urbanised parts of those counties... that ultimately will be a matter for NPHET."
Mr Martin said people in cities can avoid restrictions by taking action to curb the spread of the virus.
It comes as the Government has told all third-level institutions to hold as many classes online as possible for the next three weeks.
