Donegal is the second county to be moved to level 3 Covid restrictions after an emergency Cabinet meeting.
However, Cork, Louth, Waterford, Wicklow, Kildare and Galway now have worrying levels of the virus and the Taoiseach has warned that "there is every chance" other counties will be moved to level 3.
Micheál Martin has this evening announced that stricter measures will be imposed in Donegal for the next three weeks. The restrictions will come into force from midnight tomorrow.
The county now has an incidence of 148 per 100,000 which is the highest in the country.
Social gatherings such as Communions, weddings, birthday parties and other family events have been blamed for a large number of the cases in Donegal.
A total of 324 new cases of COVID-19 have been confirmed today, with 167 cases in Dublin, 42 in Donegal and 34 in Cork.
While so-called 'wet pubs' in Dublin have been closed under measures imposed last week, pubs in Donegal will be able to remain open but only to serve 15 customers outdoors.
Acting CMO Dr Ronan Glynn said that the situation across the country is concerning and said everyone now has to make sacrifices to keep the virus under control.
"I do not want to be back here next week or the week after," Dr Glynn said after NPHET advised that Donegal be placed on level 3 of restrictions.
"Keep your distance, wear face coverings and don't go to work, don't send your children to school, don't interact with others if you have any symptoms," he said.
Dr Glynn said he understands that people are now eager for normal life to return “but this is precisely the opportunity that this virus has been waiting for”.
He added that Covid doesn’t care about county boundaries or the border.
In the past 14 days there have been 3,600 new Covid cases and there are now 16 people in intensive care units.