Whanganui will remain at Covid-19 alert level 2 until 11.59pm on September 6.
Prime Minister Jacinda Ardern announced at 3pm today that level 3 restrictions which were to apply until Wednesday would be extended.
The announcement came after Cabinet met today and took into account the advice of director general of health Dr Ashley Bloomfield.
The factors Cabinet considered include the number of new cases, the types of cases including those unconnected to the current cluster, the capacity of the contact-tracing regime and the health system, economic impacts and the levels of public compliance.
Whanganui mayor Hamish McDouall said he thought the Government had made the right choice.
"Obviously it's disappointing but necessary," McDouall said.
"While there is still community transmission in Auckland it's important that they stay at level 3 while we remain at level 2."
McDouall said he appreciated the distancing restrictions were tough for hospitality businesses and sporting events.
"There was a very small crowd at Wembley Park when we went to the kids' sports on Saturday.
"I urge everyone to keep practising safe distancing as well as good hygiene and handwashing."
Air Chathams general manager Duane Emeny said it was not the news he was hoping for but his company was prepared for an extension of the current levels.
"Obviously having to cancel regional flights to and from Auckland has taken a huge economic toll on the business.
"We were just getting back on our feet after the level 4 lockdown but it's out of our control."
Emeny said the company was well prepared for mask use and special cleaning procedures when they did start flying again.
"We will re-implement the level 2 procedures we had in place before.
"Last time we went to level 2, we implemented our own policy so we are quite well prepared."
Air Chathams has had to reimburse a number of customers with cash or flight credits and Emeny said it would be good to get the service going again.
"We are very grateful for the support and understanding we've had from Whanganui customers."
Musician Anthonie Tonnon said his show at the Royal Wanganui Opera House on Saturday, August 29, would go ahead, but with three shows instead of one.
"We're aiming for three separate shows, all with 100 capacity, and all held on the Saturday," Tonnon said.
"There'll obviously be a bit of shuffling and rearranging to do, but we felt that we needed to honour our commitment to people."
Tonnon said the show would still be streamed online at 8pm on Saturday as planned.
The alert level restrictions next week - level 2 around the country, including Auckland - will be in place for a week and be reviewed on September 6.
Cabinet also decided to make masks mandatory on public transport at level 2 and above from Monday.
Bloomfield said exemptions might be given if there was a medical reason, and further advice was being sought about masks for children.