This comes amid fears of an outbreak of the highly transmissible Delta variant.
Last week, a Delta case was reported in Auckland, ending a six-month run without local transmission in New Zealand.
The New Zealand PM said health experts were advising her to stick with the elimination approach. She added that it was the best strategy. A total of 68 new community cases were reported on Thursday.
Meanwhile, her Australian counterpart Scott Morrison said New Zealand's policy was "just absurd" adding that "New Zealand can't do that."
Australia also followed a COVID-zero policy for about 18 months, but Delta variant outbreak in the country is making the authorities change their policy.
Ardern said she was "not fussed" by such concerns, pointing to the success of a pandemic response in New Zealand, which has resulted in just 26 deaths among a population of five million.
"We wanted to save people's lives, and we have; We wanted to try to have people's lives lived as normally as possible, and we've had some of the shortest periods of restrictions of any country," she said.
"And we wanted to save jobs and the economy, with the economy running at pre-Covid levels, we've done that too."
Ardern said Delta had forced tweaks to the elimination strategy -- such as a faster national lockdown and more extensive testing -- but it was still a valid goal.
She said New Zealand could examine alternative policies when it improved vaccination rates, which are currently among the lowest in the developed world, with about 20 percent of the population fully inoculated.
"No one wants to use lockdowns forever and that is not our intention... but for now, while we vaccinate, elimination is the goal and we can do it," she said.