Northern Ireland Education Minister Peter Weir, along with other education ministers, has been warned not to reopen schools prematurely by a group representing British and Irish teacher trade unions.
The general secretaries of ten teacher trade unions across the UK and Ireland have written to education ministers urging caution as several governments discuss lockdown exit strategies.
Jacquie White, of Ulster Teachers' Union, warned of a risk transmission rates might spike if schools are opened prematurely, as well as operational challenges.
The letter was sent by the British Irish Group of Teacher Unions (BIGTU) on behalf of almost 1 million teachers and education staff in five jurisdictions.
Schools in Northern Ireland have been closed to all but a small number of pupils since late March due to coronavirus.
First Minister Arlene Foster has previously said that was likely to last until the summer, but the Executive is meeting this week to discuss a lockdown exit strategy.
However, Prime Minister Boris Johnson is expected to set out a plan to reopen schools on a phased basis in England, while schools in Wales may admit more pupils early in June.
Schools in the Republic of Ireland will remain closed until September at the earliest.
Teachers warned of a need for the capacity to "test, trace and isolate" and said opening schools before a regime is in place could be "catastrophic" to the rate of infection.
They also said schools can only operate safely if proper social distancing is in place, along with strong hygiene practices and the use of PPE.
The letter read: "This will mean that as schools cannot reopen as normal, a phased return will be required and priorities established around attendance, which is likely to be part time for most pupils."
They also urged ministers to consider equity when it comes to reopening schools and the "trauma" suffered by children in lockdown.
"We recognise that children from poor and challenged backgrounds and vulnerable children will inevitably require significant additional support as we move slowly back to a more settled situation.
"We need to recognise, also, that potentially all children will have suffered a level of trauma as a result of the COVID 19 pandemic and we would urge that the initial focus when schools reopen, in any capacity, should be on the health, well-being, and emotional resilience of our students."
The letter was sent to Gavin Williamson in Westminster as well as Dublin Education Minister Joe McHugh, along with Kirsty Williams in Wales and John Swinney in Scotland from unions including NASUWT, TUI and INTO.