Three-layer face coverings will be mandatory on public transport in Wales from 27 July, the first minister has said.
At the daily Welsh Government coronavirus briefing, Mark Drakeford said this would also be the case for taxis and other situations where 2m social distancing was not possible.
Last week, Health Minister Vaughan Gething recommended their use.
But he stopped short of making them mandatory.
Mr Drakeford said: “For the sake of simplicity and consistency, as well as being part of our plan to help reduce the risk of transmission while on public transport where it is not always possible to maintain a two metre physical distance, it will become mandatory for people to wear a three-layer face covering while travelling – this includes taxis.”
Face coverings are currently required on public transport in England, Scotland and Northern Ireland.
Having a different rule for wearing masks on public transport in Wales and England was “not sustainable in the long term”, Mr Drakeford said.
“Our decision to make face coverings mandatory on public transport is a combination of the fact that we know as the economy gets back into operation more people will need to use public transport to go to work and for other purposes, and when more people need to use confined spaces then additional protections need to be introduced in order to overcome the fact that two-metre social distancing will not always be possible,” he added.
Taxi driver Stephen Clifford, from Newport, does not believe it will work for customers
He said: “Most of people the customers wouldn’t wear them.
“We’d lose an awful lot of money. If you’ve got to have it, you have got to have it. And what if we had to provide them? It’s hard to say.”
Asked why coverings were not mandatory in other public spaces, Mr Drakwford said: “The advice of the Welsh Government is that if places are crowded then face coverings are advisory. Where places are not crowded it is a matter for the individual citizen to make that decision.”
Coronavirus is now “at its lowest ebb” since the pandemic began, he added, saying the Welsh Government’s response had to be “proportionate”.
While Mr Drakeford said masks would not be mandatory for shoppers, businesses may ask people to wear them.
He said the retail sector had made “huge efforts” to introduce measures to maintain physical distancing, including putting up one-way systems, limiting the number people who can enter a shop and putting up screens at checkouts.
But, he added: “At this point in time, when the prevalence of coronavirus is low, we are not mandating the use of face coverings in other public places, but many people may choose to wear them – and there is nothing to stop that happening in Wales.
“Our advice may change if cases of coronavirus begin to increase.”
The first minister said the Welsh Government had made changes to regulations which recognise there are some occasions when it is not always possible to maintain a distance of 2m.
“These include maintaining hygiene standards and limiting close face-to-face interaction, wherever reasonable,” he added.
Mr Drakeford also said 300,000 coronavirus tests have been carried out in Wales, with 17,000 of them positive.
He urged people to carry on following the “golden rules” such as washing hands frequently.
He said there had been a “real change in working patterns, with more people working from home”, adding: “We need to see flexible working become a permanent feature of working life in Wales and the Welsh government will lead the way in this.”