New Zealand Prime Minister Jacinda Ardern was sworn in for a second term Friday, as final election results showed her landslide victory was even bigger than previously thought.

The charismatic leader and her ministers made their oaths of office in English and Maori during a ceremony at Wellington's Government House.

“I would say simply that sitting at this table is Aotearoa New Zealand,” Ardern said, gesturing to her gathered team, in which women and Maori are strongly represented.

“They collectively represent a range of different perspectives, huge talent, enormous experience and, as you would expect in any time of crisis, a huge commitment to serving this country.”

Ardern, 40, leveraged her success battling Covid-19 into an unprecedented majority at the October 17 election, leading her centre-left Labour Party to its biggest win since World War II.

Final results released Friday showed Ardern won 50 per cent of the vote, up from 49 on election night, giving her 65 seats in the 120-strong parliament, rather than 64.

The main opposition National Party saw its seats reduced from 35 to 33, prompting campaign director Gerry Brownlee to step down as deputy party leader.

Ardern said she had a clear mandate for reform, although her priorities were containing Covid-19 and rebuilding the virus-damaged economy.

Incrementalist reform

The pandemic is one of a string of emergencies that tested Ardern's leadership during a torrid first term, after she rode to an unexpected victory in 2017 polls on the back of a wave of support dubbed “Jacinda-mania”.

She displayed both empathy and decisive action on gun control after a white supremacist gunman killed 51 Muslim worshippers in the Christchurch mosques attack last year.

Ardern again found herself comforting a shocked nation when a volcanic eruption at White Island, also known as Whakaari, killed 21 people and left dozens more with horrific burns.

While praised for her crisis management, Ardern was criticised during her first term for failing to deliver on key promises such as improving housing affordability, protecting the environment and reducing child poverty.

Since the election, Ardern has signalled she wants reform, but not at a rate that would alienate the centrist voters who switched support to Labour in the poll.

“We must make sure we represent all those who elected us, be they in city seats, rural seats, general seats or Maori seats,” she told reporters Friday.

She had flagged action on infrastructure projects including increased state housing and more renewable energy, as well as a determination to tackle issues such as climate change, poverty and inequality.

Edward Elder, a teaching fellow specialising in political communication at the University of Auckland, said Ardern was likely to take an “incrementalist” approach to reform.

“It really depends on what the Labour government thinks they can implement to create long-term change, rather than overreaching, facing a harsh backlash, and having National come in after 2023 and simply reversing all their decisions,” he told AFP.