Education Minister Norma Foley has rejected claims adequate resources have not been provided to ensure testing and tracing could cope with the pressures of schools re-opening.
Thousands of school children are restricting movements after being deemed close contacts of confirmed coronavirus cases.
But Minister Foley does not believe schools have been let down by the Department of Education.
On Wednesday, school principal Simon Lewis told Newstalk the current system to combat COVID-19 in schools was 'a firefight and a hope'.
He said: "I suppose my main frustration has been when we were alerted to a case, it was in the evening time from a parent.
"And we had to wait until 9 o'clock the next morning before we were able to contact a special principal hotline - it only opens at 9 o'clock in the morning.
"They take a couple of details, and then you have to wait up to 24 hours before someone comes back to you for contact tracing."
And he also said there was "a lot of fantasy" around some measures, such as pods and two metre distancing in classrooms.
"The reality is we haven't been given enough to absolutely keep schools as safe from this virus as we should have been", he added.
But Minister Foley told The Pat Kenny Show: "I don't accept that, I think we have resourced our schools incredibly - 650m of resource has gone into our schools, providing a variety of prevention infection [sic] control measures.
"And that's everything from enhanced cleaning, PPE, substitution - all of the things that were needed and directed by public health.
"And in relation to the carbon dioxide monitors they are also being rolled out in our schools.
"We ordered them more than four months ago now; there is an international demand on them.
"More than half of our schools have received them, will be receiving them in tranches, all of our schools will have them."
Pressed on why these were not in place for when schools re-opened, she said this is down to demand.
"We made the decision that we would order them centrally so that no school would have the responsibility or the onerous task of going out themselves seeking to find Co2 monitors.
"They will be in our schools before the end of the month."
And asked about the possibility of contact tracing being faster, she says people do not need to 'second-guess' the HSE
"To be fair, I want to be very clear, no principal is being asked to second-guess the HSE or public health.
"And we were very clear in that respect, and that's why the school teams were set up".