The HSE CEO echoed the Taoiseach's comments that a ransom will not be paid.
The HSE made "steady and safe progress" overnight in assessing the damage of Friday's cyber attack and working to regain control of its IT system, according to CEO Paul Reid.
Early on Friday, the HSE announced it had temporarily shut down its IT system after it was targeted in a "significant ransomware attack".
Described as possibly the most significant cybercrime attack on the Irish state by Minister of State for eGovernment Ossian Smyth, it has caused major disruptions to health services across the country.
Speaking on RTÉ's
Saturday with Katie Hannon, Reid explained: "Teams have been working throughout the night... The best way to describe it is they've made steady and safe progress overnight."
The CEO said this involved re-gaining access "to the base layer" of the HSE's network, identifying the nature of the attack and looking into what systems could be brought back in a safe manner.
Reid stated that the cyber attack was "most likely" carried out by an international criminal organisation and echoed
Taoiseach Micheál Martin's comments on Friday night that a ransom will not be paid to the perpetrators.
He said: "No State wants to leave its national infrastructure exposed to ransoms and that's exactly what these organisations set out to do."
Reid also said the HSE does not have indications yet in terms of what patient data has been accessed and confirmed health services across the country will be impacted into next week.
The CEO advised patients looking to access health services: "Stay very close to our
HSE.ie site. We're updating it regularly throughout the weekend.
"If patients have appointments across all different services, we will be in touch. Watch our site, what it's saying."
That said, Reid stated that the pathway for Covid-19 testing has continued, along with vaccinations. He also assured the public it was safe to register for a vaccine through the HSE's portal.
"[We] very much encourage everybody to do it. For a brief time yesterday, we took that online system down... We did all the testing on that and that's up and running functionally perfect," he explained.
