The Chief Executive Officer of the HSE Paul Reid has said that the impact of the cyber attack on the health services is "quite grave" in the immediate term.
Speaking at the latest HSE briefing, he said the attack was "catastrophic" on the health system, and a "stomach-churning criminal act".
Mr Reid also said that the act was an attack on humans, carried out by people against people, against some of the most vulnerable in our society.
He said it was "a callous act" and an attack on healthcare workers, who have worked relentlessly for 15 months, many making personal sacrifices and taking risks.