The Stormont health department say the move, which is currently being weighed up by UK Health Secretary Sajid Javid for NHS staff in England, could worsen the staffing crisis in the health service here.
Northern Ireland currently has a shortage of staff, with the nursing profession the worst impacted.
Vaccination is already a mandatory requirement for care home staff in England but not in Northern Ireland.
A spokesperson for the Stormont health department said that while Health and Social Care (HSC) staff are encouraged to take up the offer of vaccination against coronavirus, the “vulnerable staffing position” could be destabilised by a move to make it a mandatory requirement for employment.
On Monday, the UK Health Secretary told Sky News: “There are around 100,000 [NHS staff] that are not [vaccinated] at this point.
“But what we saw with the care sector is that when we announced the policy... we saw many more people come forward and do the right thing and get vaccinated.
“That’s what I hope, if we can do the same thing with the NHS, we will see.”
He added: “I’m leaning towards doing it.”
Mr Javid later echoed that view in an interview with BBC Radio Four, saying mandatory vaccination for NHS staff is the “direction of travel”.
The News Letter asked the Department of Health whether it is considering a similar move.
A spokesperson said: “The Department of Health continues to work with HSC employers to maximise uptake of the COVID-19 vaccine amongst health and social care staff.
“We encourage all staff who are not yet vaccinated to do so without delay. Vaccination is the most effective way of stopping the spread of COVID-19 and protecting people against serious illness.”
The spokesperson continued: “We do not want to take a position that might further destabilise our vulnerable staffing position and therefore have currently no plans for a mandatory vaccination programme at this time.
“This is consistent with the approach in Scotland, Wales and in the Republic of Ireland.”