Asked if she would stay on if in Opposition, Ardern said she did not want to speculate about what would happen with any of the minor parties or the effect on the election result.
"But nor have I got into a situation of declaring what would happen if we weren't successful.
"My focus has to be on the last five days of getting Labour into a good position."
At current polling, NZ First will not make it back into Parliament and the Greens are hovering just above the 5 per cent party vote threshold.
Ardern said the Greens were not to be feared.
"You hear a lot of fear-mongering at election time, often from the National Party, but people need to just look at the reality of the last three years.
"They've already seen them in Government."
She said MMP guarded against "lurches" in either direction on the political spectrum.
Ardern was interviewed by broadcaster Mike Hosking this morning in the final instalment of the Newstalk ZB Leaders Breakfast series.
LISTEN LIVE HERE OR WATCH ABOVE
JUDITH COLLINS
Ardern said National leader Judith Collins was a "very different" opponent to 2017 leader Bill English.
She and New Zealand voters knew English better than Collins, she said. And the National Party was very different under Collins.
Ardern said she respected anyone who took an Opposition party into an election campaign.
"It is not an easy job, particular when you've got a bit of transition and rebuilding."
Ardern said she was a better leader than three years ago.
"I have learned how to use the levers to move more quickly - that is one of the frustrations I've always expressed with Government, things always take longer than you expect."
She had also learned how to manage New Zealand through a crisis, she said.
"It's actually the things you come up against that you don't expect that matter as much as the things that you do."
GRIEVING FAMILY
Earlier, Ardern said she would reconsider a decision to deny a grieving British family entry to New Zealand.
Ardern said this morning that she stood by a decision not to let yachts in the Pacific dock here during the Covid-19 pandemic.
She said she did not want a scenario in which people could not fly into New Zealand but could sail in.
Some yacht owners wanted to come to New Zealand for insurance reasons - because it was cheaper to dock in this country - and that was not reasonable grounds for coming here, she said.
But she said she would go back and reconsider whether a British family whose son had died while at sea should have been allowed to dock here.
"I am going to go back and have a look at that one," she said.
Barbara Genda and Harry Jarman have been stranded in French Polynesia since the death of their son Eddie. They were denied access to New Zealand, where they wanted to dock so they could sail their boat and fly home.
GANGS
Ardern said the large rise in the number of gang members could be traced back to 2011, and was not a The main factor was Australia's deportation of criminal and gang members to New Zealand, she said.
As well as increasing police numbers, the Government needed to take a social approach too, looking at why young people joined gangs in the first place.
CHINA
Ardern said New Zealand needed to diversify beyond its reliance on China.
Asked by Hosking whether China was "Machiavellian", she said: "No more so than some of the other engagements that we have.
Asked to elaborate, she said: "We have seen a change in strategy from the United States."
She said when countries tried to discuss fair taxation for multinationals with the United States they could now be hit with trade sanctions.
COVID-19 AND CANNABIS
Ardern said she did not believe director-general of health Ashley Bloomfield had been too conservative in his response to Covid-19.
She said he was a studious, evidence-based and optimistic leader, and pointed to the 30,000 people at the All Black test in Wellington yesterday as evidence of "how far he has helped get us to where we are today".
Ardern said she did not regret keeping her vote on the cannabis referendum a secret.
She said she had spoken often about her positions on recreational cannabis use in the past.
She had previously said that young people should not be able to access cannabis, and that people should not be unnecessarily criminalised for cannabis use.
HOUSING
Ardern defended her government's widespread use of reviews and working groups, saying they had led to significant proposed reforms of the health sector and the Resource Management Act.
"I don't resile from the use of experts coming in and helping us with reform when it's needed."
Hosking pointed out that housing had not become more affordable in New Zealand under her government's watch.
Ardern said the housing costs had built up over decades, not just the last three years, and the key solution was increasing supply.
She noted that there were now more first-time buyers in the market. She rejected the suggestion that this was solely down to low interest rates, saying that the government had provided new products for this group and eased demand through policies such as a ban on non-resident buyers.
On Kiwibuild, Ardern said it was difficult to build at the original, proposed scale - 10,000 houses a year.
She said the Government was also trying to get first home buyers into new areas, and some people could not be convinced to buy within new housing developments.
She did not regret the Kiwibuild policy, and said people had underestimated that effect it had on the housing market.
"It has created an extra trigger for affordable housing," she said.
On social housing, she rejected the suggestion that making it easier for people to stay in state houses for longer had contributed significantly to the growing waiting list.
She said it was largely down to this Government not rejecting applicants in the same way as the previous government.
Her Government had ramped up social housing construction, she said.
"If we keep building at the rate we are, we will get rid of that wait-list."
MINISTERS
She disagreed that her party lacked depth.
"I back everyone who sits at my Cabinet table."
She defended controversial ministers Phil Twyford and Kelvin Davis.
Speaking about Davis, the Corrections Minister, she said the prison population had been safely reduced, and the work he had done on Crown-Maori relations was "taking us into a new era".
She noted that Labour had not lost 19 members - as National had.
Asked about the three strikes policy, she said that the judge should be able to determine the sentence of a repeat offender.
Under three strikes, there could be "perverse outcomes" such as a person who engages in low level property crime getting locked up for an extended period.
FARMING AND FAIR PAY
Ardern said talk of an urban-rural divide came up every election and she did not believe it existed.
The Opposition had tried to promote the idea that farmers hated her Government.
She said Labour's approach to farming was adding value to an already valuable sector.
Ardern confirmed that the Government would try to progress fair pay agreements if it was re-elected, having been unable to do so this term because of coalition wrangling.
She said having sector-wide agreements were important to "avoid a race to the bottom".
When a firm was contracting for security services, contracts often went to companies which had the lowest standards and conditions - and the Government wanted to change this.
The agreements would not affect every workplace and were sector-specific, she said. There would be no strike action as a result of the agreements.
PIKE RIVER
Ardern stood by the recovery mission at the Pike River coal mine, despite rising costs and no discovery of remains.
"We have always known that there might be a chance that we might not find human remains," she said.
She said the Government owned it to the family to attempt a recovery. It would remove a question that had hung over families and the country for a decade, she said.
COALITION PARTNERS
The first section of the interview focused on Labour potential coalition partners and their main policies.
Ardern said the Green Party's wealth tax was not Labour policy and it would not be part of any post-election negotiations. She said the major party forming a government should set the direction on tax policy.
"We have ruled it out. And I've done it multiple times."
Ardern also said she had not had any negotiations with other parties about possible ministerial portfolios, saying it was presumptuous.
Asked about any possible new taxes, Ardern said her party's "primary" proposals were a new top tax rate and a digital services tax.
Hosking said the most popular question for Ardern from listeners was about Ihumātao.
Ardern said just one person had raised it on the campaign trail.
She blamed the impasse over Ihumātao on MMP, saying that NZ First leader Winston Peters had prevented any progress at the site.
There was no secret deal, she said: "We have to find a way through."
The historic site near the airport in South Auckland was occupied by protestors last year who opposed a proposed development. Construction has been put off until an agreement can be made between the Government, various groups within the iwi, and the construction company Fletchers.
Ardern said her bottom line for the situation was that it could not "unravel" the Treaty process.
"Any gifting of land would be problematic in that regard."
THE ECONOMY
Ardern was next asked how long the government could keep supporting the tourism industry if the borders were going to be closed for an extended period.
She said the Government was backing strategic industries with one-off payments - such as Whale Watch in Kaikoura.
Asked how she would describe New Zealand's economic position, she cited a Bloomberg article which described New Zealand as one of the most attractive places to do business.
"[We are] well placed relative to others and that matters," she said.
"We have an opportunity here - not just because we have an open economy - we have an opportunity around investment."
LEADERSHIP
"That's why I'm campaigning, why wouldn't I?" Ardern responded when asked if she'd serve a full term if relected.
She wouldn't reveal if she would stay on for another three years as Leader of Opposition if voted out.
Ardern yesterday laid out a longer-term vision for New Zealand at a party rally in Wellington.
She said she wanted the state housing waiting list to be zero by 2030 and child poverty to be halved.
The state house waiting list is currently about 20,000, up from about 6000 when the current Government took power. It has built about 4000 new state houses but that has not kept up with demand.
And halving child poverty by 2030 is actually less ambitious than the Government's 10-year targets, announced in January 2018, to do just that by 2027/28.
Her 2030 vision also included a New Zealand with no health inequalities based on race, wealth or geographical location, with swimmable rivers, and with farmers selling IP to the world on how to reduce emissions.
With less than a week to go until election day, the Labour leader is in the box seat.
The latest poll last week showed her party was holding a large lead over National.
But at 47 per cent of the party vote, it still needed the Greens (6 per cent) to form a government. National was on 32 per cent and Act 8 per cent, meaning they fell short of forming a centre-right government.
Ardern last week released new policies on law and order and climate change, and made visits to Christchurch, Nelson and Dunedin.
Previous Leaders' Breakfasts
• Judith Collins
• Winston Peters, James Shaw and David Seymour