Sweeping changes to the way the health service in Northern Ireland operates are to be rolled out in the coming days in preparation for a surge in Covid-19 cases.
The Department of Health's most senior civil servant, Richard Pengelly, said it is hoped that the radical overhaul of services will help staff cope with the difficult period ahead.
Health bosses have been tasked with putting in place measures to maximise resources, which include the closure of emergency departments (EDs), minor injury units, and day case procedure and outpatient units across Northern Ireland - with no guarantee that services will return after the pandemic.
The radical changes to services come as health service bosses prepare for the possibility that 20% of staff may be off work at any one time.
Health Minister Robin Swann has also warned that up to 15,000 people in Northern Ireland could die from coronavirus, meaning many more will need hospital treatment.
In a letter sent to the health trusts, Mr Pengelly said: "Our modelling suggests that at the peak of the outbreak in Northern Ireland, our existing hospital estate may not have sufficient capacity to provide critical care to the number of patients who will require it.
"We are therefore moving immediately to develop large regional, temporary respiratory hospitals. These will be a regional resource and will require a regional approach in terms of staff and access.
"More details of how these will work in practice will be shared when they are ready."
Only two trusts have so far published details of their surge plans, with the South Eastern Trust revealing the closure of the A&E unit at the Downe Hospital from this Monday.
The hospital's inpatient wards, acute mental health and psychiatry, and old-age patients will remain open, while the midwifery unit will continue to provide community services, although women will no longer be able to give birth there.
The GP out-of-hours service will also stay open, although this will remain under review given the pressure on family doctors across Northern Ireland.
The Southern Trust has also confirmed that the ED at Daisy Hill Hospital in Newry will close from Saturday on a temporary basis as part of its overall surge strategy.
Interim director of acute hospitals Melanie McClements said: "To ensure the safety of staff and patients, we have taken the essential decision to run one ED, which will be at Craigavon Area Hospital. This means a temporary closure of Daisy Hill's ED, effective from 2pm on Saturday.
"This is not a decision we have taken lightly, but these are exceptional circumstances.
"This move allows us to consolidate our emergency, intensive care and respiratory expertise all one site which will give us a much more robust service in the weeks ahead.
"If we don't work to make these changes now, we risk services on both sites collapsing as we expect staffing levels to be impacted in weeks to come.
"Daisy Hill Hospital ED is a key part of our service provision. This is a temporary measure to deal specifically with Covid-19.
"Please be assured that this service will reopen once the immediate situation improves. In the meantime, please stay at home, wash your hands, keep your distance."
On Wednesday night, former health minister Jim Wells revealed that he had been informed of plans to shut Daisy Hill's ED in response to the spread of the virus and raised concerns that the closure might become permanent.
"The people of Newry and Mourne will fear that once this crucial service leaves Daisy Hill, it will never return," he said.
"Similar temporary arrangements were implemented at Belfast City and Lagan Valley hospitals eight years ago and there has never been the slightest suggestion that the A&Es will ever return to either site.
"Normally such a major reduction in the service available at a hospital would be the subject of a lengthy public consultation, but the Southern Trust is aware that the sweeping powers given to Government to deal with the coronavirus means that this does not need to happen in this case.
"The trust also knows that public meetings and rallies to protest against the decision cannot be held in the present crisis."
While the Southern Trust has firmly stated that the closure of the ED at Daisy Hill Hospital is temporary, Mr Swann refused to give any reassurances when he was pressed on the matter at the Stormont health committee.
He said: "I don't know what the health service will look like in a week's time. I will be perfectly blunt with you on that, I don't know where we will be. Our surge plans are in place to do what we have to do.
"That's why we're down a number of procedures and elective surgeries that I would have never envisaged in my time as Health Minister, I would have to tell people they would not get.
"So, to give any sort of commitment now that we will return 100% to where we were two months ago, I can't give it and I won't give it because I can't stand over it."
Mr Swann also said he is aware of supply issues relating to PPE at care homes but he is working to address this.