The President of the INMO has said the issue of hospital overcrowding cannot be solved until bed capacity and hospital staffing are both increased.
Martina Harkin-Kelly made the comments after her organisation said the number of patients waiting on trolleys for an in-patient bed increased in the first four months of this year.
The INMO said 36,043 patients waited for a bed from the start of the year until the end of April.
This equates to the highest figure recorded for that period since records began, and represents a 1% rise on the 2016 figure.
However, the organisation noted that while the level of overcrowding is increasing, the rate of increase is slowing down.
The four-month figure showed a drop in overcrowding in hospitals in Dublin, but hospitals outside the capital showed what the organisation called "significant increases in the level of overcrowding".
The INMO also said that 7,199 patients spent time on trolleys waiting for beds in April, a 12% decrease on the same month in 2016.
The decrease was in both Dublin and country hospitals.
Speaking on RTÉ's Morning Ireland, Ms Harkin-Kelly said bed capacity cannot be increased without staff.
She said the solution to recruiting and retaining more nurses is simple: pay them and value them.
Ms Harkin-Kelly said this would be the private sector solution, adding that authorities "need to start to recognise that there is a crisis amongst the nurses and midwifery profession."
The issue of overcrowding is to be discussed at the INMO's national conference, which gets under way in Wexford today.