Enda Kenny says he's "disappointed" at the decision of the INMO to begin strike action.
Nurses in emergency departments are to go on strike on December 15th, protesting at overcrowding and working conditions.
The moves will affect five of the six hospital groups - meaning up to three of Dublin's five emergency departments could be affected.
In the Dáil Enda Kenny said the outcome had been expected, but the news was still disappointing
"I accept that there are challenges in the health system on a recurring basis, not least of which is in the accident and emergency department," he said.
"I am disappointed the INMO has voted in favour of industrial action and while the outcome had been expected, obviously industrial action is not going to sort out the challenges that we face here," he added.
The result of a ballot of members of the Irish Nurses and Midwives Organisation (INMO) was announced this morning, with 92% of respondents voting in favour of taking industrial action.
The nurses will begin striking on December 15th, after giving three weeks' notice in line with health service protocol.
Initial strike action will take place in a number of emergency departments on a rolling basis, with further days planned for 2016. It has not yet been announced which hospitals will be affected by the first day of strikes.
The union says the campaign will ultimately lead to a full nationwide strike involving nurses from all Ireland's emergency departments.
The group says its members are frustrated at the increased levels of overcrowding in the departments.
INMO General-Secretary Liam Doran told Newstalk Lunchtime says they have tried everything else to get things to change.
While INMO Deputy General-Secretary David Hughes spoke to Newstalk Breakfast earlier this morning about nurses' complaints, stating that the level of frustration when meeting with the nurses was very obvious.
"This came as a result of the worst October we've ever recorded, in a situation where we had been promised that it would improve...and we decided enough was enough".
"The tolerance of this is unreal," he added. "We've been counting these trolleys for ten years, and you're told that when you 'only' have 200, you're doing well".
He added that, with their experience of counting trolleys, they know that yesterday's figure of 300 people on trolleys will only grow today, and is likely to hit 350.
Hughes highlighted that solving the crisis will need more staff, which is one of the demands being put forward: "if we have to put up with overcrowding, there [needs to be] enough staff to treat the patients".
Earlier this month Health Minister Leo Varadkar said he does not think industrial action by nurses will do anything to get patients off trolleys in emergency departments.
However he added there will be negotiations between the union and employers to figure out what can be done to address the current situation.
