On a visit to New Zealand, the United Nations chief has rebuked a key policy of the Luxon government to resume exploration for oil and gas.
UN Secretary-General Antonio Guterres landed in Auckland on Friday, en route to the Pacific Islands Forum Leaders Meeting in Tonga next week.
He has made progress towards the global body's climate goals his primary issue while leader of the global body.
On his stopover, Mr Guterres met with Prime Minister Chris Luxon and his deputy Winston Peters - also the foreign minister - separately.
Mr Luxon and Mr Peters have both championed the reversal of a 2018 ban on offshore oil and gas exploration imposed by Jacinda Ardern's government.
Additionally, the coalition government has stripped away many of the previous Labour government's initiatives to reduce reliance on fossil fuels.
Mr Guterres said he did not raise New Zealand's intention to extract more fossil fuels in his meetings, but said any attempt to do so would be in vain.
"The only thing I can tell you is that the oil and gas that will be discovered from now, I'm absolutely sure, it will never be used," he said.
Oil and gas projects have long lead-in times from discovery to extraction: NZ media outlet Newsroom reports an average time of 16 years between a permit being issued to production.
Mr Guterres arrived from Samoa, where he visited climate adaptation and mitigation projects.
"My presence at the Pacific Islands Forum is essentially an expression of solidarity with the Pacific Islands," he said.
"They do not contribute to climate change and they are in the first line on the negative impacts."
Mr Guterres' message of climate action is aimed squarely at developed economies, which are responsible for 80 per cent of global emissions.
"They need to change," he said.
"They need to take seriously climate action. Phasing out fossil fuels and adopting all the measures necessary to reduce drastically the emissions in the present."
