Irish hospitals are totally dependent on nurses from non-EU countries, according to the General Secretary of the Irish Nurses and Midwives Organisation.
Her comments come as nurses began a series of early afternoon protests to highlight staff shortages ahead of what they say will be the worst winter ever for overcrowding.
Speaking on RTÉ's News at One, Phil Ní Sheaghdha said University Hospital Galway had recently recruited 20 nurses from India, adding that without those nurses there are beds that would have to close.
She said 169 posts remain unfilled in Emergency Departments alone.
Ms Ní Sheaghdha also said that everything the Health Service Executive had tried, bar raising pay, had failed to attract people to the positions.
In response to a statement from the HSE which said that the number of nurses employed in EDs had increased by 22% from the end of 2015 to now, Ms Ní Sheaghdha said what was not being included in those numbers was how many nurses had left in that same period.
She said there was a lack of focus by the HSE on making the case early enough in the year for the winter plan. She said planning in September was too late to "beat the rush".
Responding to questions from RTÉ, the HSE said it is spending around €1.4 million a week on agency nursing.
The HSE also said that while there are 169 posts currently unfilled across 29 Emergency Departments, it should be noted that a significant number of these are currently being filled by these agency staff, and by overtime working arrangements.
They said discussions are ongoing with the Department of Health in relation to funding for an additional 57 nursing posts.
The HSE statement also said that winter planning is currently well under way and the organisation is working with the Department, Hospital Groups and Community Health Organisations to finalise plans as quickly as possible to ensure preparedness for winter.