In the first clear sign that more curbs could be on the way, Mr Varadkar said he expects the Omicron variant to be the dominant strain of Covid-19 in Ireland before Christmas Day.
The Tánaiste described it as “frustrating, depressing and disappointing” that Government would now have to “change tack” due to the rapid spread of Omicron in the community in recent days.
It comes as European Commission president Ursula von der Leyen said she expected Omicron to be the dominant variant in Europe by mid-January.
Mr Varadkar said Omicron is likely to cause an additional wave of infection in the coming weeks and will be dominant as early as next week and “possibly before Christmas Day”.
The Tánaiste said it was “necessary” that Government would have to change course as the “priority is to protect public health, people’s lives and to ensure our health services aren’t overwhelmed in the weeks ahead,” Mr Varadkar told Pat Kenny on Newstalk radio.
Mr Varadkar described Nphet’s meeting with Government last night as “routine” but he added that he expects some further recommendations from Nphet tomorrow, and that he imagined Cabinet will convene on Friday to discuss these recommendations.
“I would expect on Thursday that there will be some recommendations on the management of close contacts, some recommendations designed to decrease the amount of social mixing and also some recommendations around international travel.
“When it comes to international travel, it will be a slightly different approach. The WHO has rightly said that restrictions on international travel are of little benefit and so I’d expect to see recommendations in those three areas,” Mr Varadkar said.
The Tánaiste said if it is the case that restrictions are required to protect life and public health and ensure our public health services are not overwhelmed, “then that’s what we will do”.
Mr Varadkar said Government had hoped current restrictions would be adequate until January 9, but the arrival of Omicron and “the speed with which it’s growing changes that picture”.
“Nphet will meet tomorrow, Government will consider that advice and I imagine we will be able to inform people very soon as to what the picture will be like in the run-up to Christmas and well beyond that.
“This is a constantly changing situation, unfortunately, and the one thing I would love to be able to give people is clarity and certainty but there is nothing clear or certain about the pandemic.
“It’s the role of the Taoiseach to convene a Cabinet meeting, as of now a Cabinet meeting isn’t planned but I anticipate that we will do that. It’s better to do these things quickly than leave people speculating or worrying over the weekend,” Mr Varadkar said, adding that there will be a “few days” notice before any rules would kick in.
Mr Varadkar said that Omicron is more transmissible than Delta and even if the severity of Omicron turns out to be lesser than Delta, “if it's twice as transmissible and half as severe, that’s still just as bad in terms of the impact on the health service”.
The Tánaiste said that frontline staff will be asked to work through the Christmas period as it will be “all hands on deck” to get as close to two million people boosted by the New Year as possible.