The Kiwi foreign minister also cast doubt over whether NZ would continue to offer generous climate finance when the current budget runs out next year.
Mr Peters was a sole voice downplaying the climate crisis on the same day the United Nations released a report forecasting growing sea level rise and flooding events across the region.
Secretary-General Antonio Guterres' attendance at the regional forum has brought a sharp focus to the devastating impacts of global warming in the Pacific.
However, asked by a Tongan-New Zealand journalist whether he believed in climate change, Mr Peters prevaricated.
"Do I believe in climate change? The answer is for thousands and thousands and thousands of years there has been climate change," he said.
He suggested said a severe storm which killed 11 people in New Zealand in February 2023 was no different to those in years gone by.
"Cyclone Gabrielle happened in the 30s in the Hawke's Bay," he said.
"The biggest tsunami in recent times was in 1968. There's always climate change.
"There have been massive climate changes down over (millennia). There was a mini-ice age in the 1600s. We all understand that.
"Our job is to build as much as we can resilience against it and whilst we're transitioning to a new age."
Mr Peters' comments jarred against the advocacy of Mr Guterres in Tonga this week, and of other Pacific leaders.
The UN chief issued a "global SOS to Save Our Seas" from rising sea levels, calling it a "crisis entirely of humanity's making" and a "a worldwide catastrophe putting this Pacific paradise in peril".
Pacific Island nations are in grave danger.— António Guterres (@antonioguterres) Relative sea levels in the Southwestern Pacific have risen even more than the global average.But what happens here doesn't end here.Surging seas are coming for us all, threatening coastal areas around the world.The world must… pic.twitter.com/AWbY4pY8i9August 27, 2024
Tuvalu Prime Minister Feleti Teo said he was delighted that the UN was platforming the climate cause.
"We're very grateful for the UN secretary-general's commitment to the cause of the Pacific in terms of climate change and of course (reducing) fossil fuels is at the core of it," he told AAP.
Papua New Guinea Prime Minister James Marape said he "could not be more satisfied" by Mr Guterres' advocacy.
One of Mr Guterres' key requests is that developed nations offer more to developing countries to help them adapt to climate change, given they largely didn't cause it.
New Zealand committed $NZ1.2 billion ($A1.1 billion) in climate finance between 2022 to 2025, meaning a new decision must be taken on how much to give in next year's budget.
The coalition government has undertaken major cuts in public spending since taking office, including to an array of climate projects.
Asked whether he would be able to maintain a level of spending, Mr Peters cryptically said, "It is extraordinary difficult in this job, but not impossible".
He is in his third stint as NZs top diplomat, but also the leader of New Zealand First, a minor party that has flirted with conspiratorial beliefs including climate denialism.
His deputy leader Shane Jones told parliament last week, "I belong to New Zealand First, not climate first".
Mr Peters' comments in Tonga align with his party's belief that economic development underpins all other matters.
"If we're going to help anyone with all the other tsunamis coming their way, such as the health tsunami, food supply tsunami, employment and economic tsunami ... we need to have a sound economy ourselves," he said.
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