There were 4,570 cases confirmed on Monday.
Micheál Martin has said that the Covid situation in Ireland is "getting worse and will get worse before it gets better".
The Taoiseach made the comments while en route to a cabinet meeting on Tuesday morning (16 November).
"Any decisions that we take, I think, we will give notice, but the situation, certainly from the presentation, from the HSE last evening, was one that does demand very quick action in respect of easing that pressure on the acute hospital system over the next number of weeks", he said.
"Case numbers are very high, and the numbers then that will inevitably end up in hospital increases with that.
"So we've got to make decisions today, but also I think collectively as a society, we've got to look out for each other, and just be very aware that the situation is getting worse and will get worse before it gets better."
According to reports, in a meeting with the Cabinet Covid Committee on Monday evening, NPHET warned the government that between 400 and 500 people could require intensive care beds in December, with a possible 2,200 people in hospital being treated for Covid-19.
The revised modelling is suggesting that large case numbers could continue to be confirmed until as late as February 2022.
Cabinet is set to discuss the latest recommendations from NPHET, including introducing the use of vaccine passports in more venues such as gyms and hairdressers and speeding up the booster vaccine programme to combat waning immunity.
The booster vaccine could soon be available for those over 50 and people with underlying health conditions.
The Irish Medical Organisation has blasted the government's current winter plan for dealing with the virus, describing the measures as "
a sticking plaster to cover a gaping wound".
"Every doctor and healthcare worker is working beyond capacity right now and it is untenable that they are being asked to face into a winter with insufficient support”, said Dr Ina Kelly, president of the IMO.
