The decision to move to level 5 Covid restrictions is a "pre-emptive strike" to bring the virus under control, the health minister has said.
Stephen Donnelly has also said he should have been told of the serious pressures on contact tracing over the weekend which lead to Covid positive people being asked to alert their own close contacts.
He said: "There are numerous ways in which the government could have been told. I'm in contact with multiple people in the HSE on an ongoing basis and so are people in the Department, but this was an operational decision taken by the HSE."
He said for a "short period, demand did outstrip supply" but he has been assured that it won't happen again.
Mr Donnelly has now written to the HSE to ask for a report on the contracts being given out to contact tracers. He said that 800 contact tracers will be in place in the next four weeks.
Speaking about the move to level 5 restrictions, Mr Donnelly said he does expect the numbers of Covid cases to rise before we see the impact of the latest measures.
"This is a preemptive strike, it has been done in a calm and deliberate manner," Mr Donnelly said.
"The virus is at a point now where it is spreading in an awful lot of different ways.
"It is spreading in workplaces, it is spreading after sports events, it's spreading a lot of the time related to alcohol, where people congregate and get together with with alcohol, and it is spreading in households and between households.
"It is the combination of all of those reasons which requires us to move to level five this morning."
Mr Donnelly told RTÉ's Morning Ireland: "We understand there's people waking up this morning, who don't have jobs to go to. We understand there's there's college students who are having to do college online when they should be in college having the best years of their lives.
"There are people who are vulnerable to this virus, be it because of underlying conditions or age or wherever it may be who are scared, again."