Health officials are weighing up potential sites for field hospitals, First Minister Arlene Foster has said.
Among the places being assessed is Balmoral Park, outside Lisburn, she said.
It has also emerged the chief medical officers on both sides of the border are to sign an agreement to co-ordinate their response.
Six more people have died with coronavirus in Northern Ireland, bringing the total to 28.
The Public Health Agency (PHA) said another 53 cases had been confirmed, bringing the total to 586.
In total 5,885 tests have been carried out in Northern Ireland, with the vast majority negative.
The new figures also showed most cases were in the Belfast area.
In the Republic of Ireland, 17 more patients diagnosed with Covid-19 have died, bringing the total to 71. The number of cases there is now 3,235.
On Tuesday night, it was announced a 13-year-old year old boy who tested positive for coronavirus had died in a London hospital.
It comes as the biggest daily increase in the number of people who have died with coronavirus in the UK - 381 - was reported.
On Tuesday, the first and deputy first ministers held talks with ministers from the Irish government.
The North-South Ministerial Council meeting took place remotely as ministers adhere to social distancing guidance.
NI Secretary Brandon Lewis and tánaiste (Irish deputy prime minister) Simon Coveney jointly chaired the meeting, which was also attended by the two health ministers Robin Swann and Simon Harris.
After the meeting, the Irish government issued a statement saying the participants "welcomed the ongoing contact and co-operation between the respective health ministers, working in close conjunction with the chief medical officers, for the mutual benefit of all".
Speaking at the daily executive press briefing, Deputy First Minister Michelle O'Neill said the two chief medical officers would sign a memorandum of understanding, formalising co-ordination and co-operation between the Irish government and the NI Executive.
Dr Michael McBride and his counterpart in the Republic of Ireland, Tony Holohan, are expected to sign the document later this week.
Ms O'Neill said: "We all know this pandemic takes no notice of borders and it makes sense that we have a joined-up effort to save as many lives as possible across this island this is all about saving lives."
Northern Ireland's Department of Health said work was ongoing to finalise a memorandum of understanding.
Also at the briefing, First Minister Arlene Foster said a decision on where field hospital sites could be set up in NI would be made in the "near future".
Mrs Foster said Health Minister Robin Swann would "flex his own current estate for intensive care beds first" and the field hospitals would be "step down" facilities.
She suggested places being looked at included exhibition centres, such as Balmoral Park, the site of the former Maze prison.
In other developments:
- It was revealed that the Northern Ireland Executive has so far received an additional £912m to deal with the coronavirus crisis
- The Health and Safety Executive defended its decision not to visit businesses accused of not implementing measures to stop the spread of the virus. The safety body says it has received about a 900% increase in complaints
- New guidance has been issued for schools to ensure sustainable arrangements are in place for vulnerable children and those whose parents are key workers
- Emergency dental clinics are being set up in each of the five Health and Social Care Trusts for any identified Covid-19 patients as well as any other patients needing urgent treatment
- More than 10,000 people have registered an interest online in boosting the health and social care workforce
- After suspending some services, Belfast City Council has said its bin collections will return to normal from Wednesday