Officials at Dublin Airport had earlier warned of “significant queues” for passengers at the country’s main airport.
Some travelling were told they could miss flights due to the extent of the queues, with 50,000 passengers expected to pass through the airport on Sunday.
Officials pledged to try to compensate all passengers who have missed flights or had plans disrupted, if additional costs are incurred.
Taoiseach Micheal Martin, speaking from Lebanon, said the situation was “not satisfactory”.
“The minister will be engaging with them and Government will be discussing this and reviewing this in terms of the huge numbers and the delays and so on.
“It’s not satisfactory.”
Kevin Cullinane, the group head of communications for Daa, the body that runs the airport, admitted they had got things “wrong” on Sunday.
“Significantly, we did not have sufficient staff manning sufficient posts throughout the airport to cope with demand early on and hence queues built up,” he told RTE radio.
“We clearly did not have enough lanes open in security from early on this morning, for the numbers who presented themselves at that hour of the morning. And that caused obviously a compounding effect throughout the morning.”
We have to put our hands up and say we got that wrong and we wish we had more staff available this morning to rectify that situation quicker than we did
Kevin Cullinane, Daa
He pledged that Dublin Airport will try to compensate all passengers who have missed flights or had plans disrupted, if additional costs are incurred.
Mr Cullinane also said airlines were providing passengers with the option of booking different flights later on Sunday or Monday, without an additional cost.
“We will look at each case on a case-by-case basis but we’ll be doing our level best to make sure that nobody will be out of pocket for missing a flight today as a results of these queues at Dublin Airport.”
Passengers have faced lengthy waits and scenes of disorder at Dublin Airport in recent months.
The airport has previously said it is trying to rebound from the impact of the pandemic and has blamed shortages in fully trained staff working at the country’s busiest airport.
Mr Cullinane said there will be an additional 370 security staff in the airport from June.
“Clearly we didn’t have and we still don’t have sufficient numbers to cater for this,” he said.
“We have to put our hands up and say we got that wrong and we wish we had more staff available this morning to rectify that situation quicker than we did.”
He said that the situation was now “under control” at Terminal 1, but lengthy queues could be expected at Terminal 2 for the next couple of hours.
In a statement earlier, a spokesperson for the airport said: “Dublin Airport is experiencing significant queues for airline check-in, bag drop and security screening this morning as 50,000 passengers are expected to depart over the course of the day.
“Queuing outside both terminals has been deployed since early morning as part of Dublin Airport’s contingency plans for the increased numbers of passengers travelling.
“Due to significant queues inside the terminals passengers queueing outside the terminal have been advised they may not make their flight and may need to contact their airline to rebook.
“Dublin Airport sincerely apologises for the obvious frustration and inconvenience this is causing.”