US Secretary of State John Kerry has shied away from directly criticising President-Elect Donald Trump's denial of climate change and his promise to undo the Obama Administration's work on the issue.
But speaking at a press conference in Wellington today, Kerry sent a strongly-worded message that the next US government could not afford to ignore climate change.
"The evidence is mounting in ways that people in public life should not dare to avoid accepting as a mandate for action," he told reporters at Premier House in Wellington.
Following bilateral talks with Prime Minister John Key, Kerry used most of his formal statement talking about "the extraordinary threat" of climate change.
When asked whether he was concerned about the next president dismantling Barack Obama's legacy of combatting climate change, Kerry said he did not want to speculate about Trump's presidency.
"I think everybody knows there is sometimes a divide between the campaign the governing, and I think the next administration needs to define itself on that subject."
Trump has described climate change as a "hoax" and promised to remove the United States from the landmark Paris Agreement and rebuild the country's fossil fuels industry.
Kerry said that in his experience, the "evidence was there for everybody to see" on human-influenced climate change.
In an apparent dig at politicians who denied it was occurring, he said "most kids in high school or even middle school are pretty good at getting a sense that something's happening".
Kerry also underlined the fact that the US first took action on climate change in 1992 under a Republican president, George H W Bush.
The Secretary of State has just returned from an "awe-inspiring trip" to Antarctica, where US and NZ scientists are co-operating on climate science.
While there, he learned from New Zealand scientists about "how fast this danger is coming at us".
On a helicopter ride over the West Antarctic ice sheet he was warned that if the mass of ice continued to break up and melt, "as it is showing signs of doing now", the oceans will rise by up to 3.6 metres.
"That is an unacceptable reality to imagine."
Kerry also spoke about the $8 billion the US Government had spent on cleaning up storms last year which were "far more intense than any we have seen before".
Floods which were once thought of as one-in-500 year events were now occurring almost yearly, he said.
Later in his trip, Kerry will attend climate talks in Marrakech, Morocco, along with New Zealand's climate change minister Paula Bennett.
Bennett has said it would be "a real shame" if Trump removed the US from the Paris Agreement, because the US was a crucial leader on the issue and was responsible for a large proportion of global emissions.