INFRASTRUCTURE minister Nichola Mallon has said she is keeping the question of compulsory face coverings on public transport "under constant review".
The SDLP minister was speaking following calls from the Unite union for face masks to be mandatory.
As moves are made to begin easing the Covid-19 lockdown, there are fears buses and trains could become crowded by those returning to work.
Davy Thompson, Unite deputy regional secretary, called for Ms Mallon to make wearing face masks compulsory to protect workers and passengers.
"As the trade union for front line public transport workers, Unite has been making the case that drivers and other workers coming into contact with the public should be provided with face masks as a routine infection control," he said.
"We have also argued that passengers be required to wear face masks during their journeys in order to better protect themselves and our members".
He added: "It is not enough for the minister to recommend the public wear face masks on buses and trains - we need to see them made compulsory.
"Our drivers’ lives and those of fellow travellers are at stake - we need every possible protection."
Ms Mallon said she was keeping the situation "under constant review".
"I understand the call from bus drivers and from Unite the union," she told the BBC.
"Last week, I raised this issue.
"I have been in contact with other ministers across these islands on this issue and the Executive took a decision based on the medical advice to recommend that people wear face coverings on public transport but I hear what the drivers are saying, I hear what Unite is saying.
"I will be seeking revised advice again from the Department of Health on this situation because we have to do everything we can to keep people safe".
