Wellington region's public transport head is still working out how to implement mask rules but says police not staff will deal with safety breaches.
From Monday, face coverings will be compulsory on public transport at any time the country is in level 2 or above.
Children will not be required to wear masks, but an exact age is being worked on. Taxis and rideshare services like Uber are included in the rule.
Greater Wellington regional council general manager of public transport Scott Gallacher said they will be moving to a mandatory rule on the use of face masks across all the network by Monday.
Gallacher said they had made a bulk order for PPE and had "more than sufficient" supplies for all Metlink staff.
Asked whether drivers have had training for safe use of masks and PPE, he said the council would work with operators and staff this week.
The council would be working with the government on whether to have spare masks to give to passengers and, if not, whether people without a mask who needed to board a bus would be allowed to do so.
Gallacher said the government didn't expect staff to be enforcement agents. "If we're presented with a circumstance where the safety of people on the bus or the train or the ferry is compromised by the actions of someone then clearly we'll be contacting the relevant enforcement agencies like the police."
"The government shared with us some initial guidance last night, they're working on how they're wanting us to implement the mandatory move."
He said they needed to make sure they were doing the right thing by vulnerable people who needed to access public transport.
The government is still working on the legal framework for making masks compulsory.
Children will not be required to wear masks, but an exact age has not yet been decided.
The type of masks being used will not be policed.
Prime Minister Jacinda Ardern, announcing the move yesterday, said people are encouraged to explore alternatives to single-use masks if they can afford to, or to fashion a mask from things found at home.
Face coverings like a bandana, scarf or t-shirt could be used.