Jacinda Ardern is defending the Government's climate change action after Swedish activist Greta Thunberg targeted New Zealand over its greenhouse gas emissions.
In a Twitter post, Thunberg linked to a piece from The Guardian on New Zealand's dairy cow emissions, which have climbed to record highs.
"New Zealand is one of the world's worst performers on emission increases. Its emissions rose by 57 percent between 1990 and 2018 - the second greatest increase of all industrialised countries," Thunberg wrote, quoting an extract of the article.
The Government in 2019 passed the Climate Change Response (Zero-Carbon) Amendment Bill, which sets a target of zero carbon emissions by 2050 and commits to global effort under the Paris Agreement to limit the global average temperature increase to 1.5C above pre-industrial levels.
But a Climate Change Commission report in June said while it was still possible to make transformational changes, New Zealand was currently not on track to meet those targets.
Ardern was on Tuesday asked if Thunberg's remarks hurt the Government.
"We are obviously in the process now of just having received our Climate Commission report, of responding to what is a significant piece of work in order to plan our emissions reductions and our carbon budgets," Ardern told reporters.
"It would be unfair to judge New Zealand based on what, essentially, are targets that were set some time ago - when we are now undertaking an incredibly heavy piece of work to lift our ambition and our emissions reductions."
Ardern noted New Zealand was a food-producing nation.
"As a result... we have the very tough job of a significant proportion of our emission coming from food production - methane - and so that does make our job harder," she said.
The UN on Monday published a report that delivered dramatic warnings about the effect of human-induced climate change on the planet and how much worse it could get.
Climate Change Minister James Shaw admitted the window of opportunity was closing.
"But there is still time if we act now," he said. "We need to act urgently and we need to act comprehensively right across the economy in every community, in every sector - to start to reduce our emissions over a sustained period of time."
The Opposition has hit out at the Government over climate change, most recently on Tuesday, after tens of thousands of New Zealand properties lost power on Monday night due to insufficient generation.
"This Government has declared a climate emergency, waged war on energy sources it doesn't like and tried subsidising those it does, but at the end of the day comes night, and there's not enough energy," ACT leader David Seymour said in a statement.
"It turns out the real climate emergency is a cold, still night in winter when all the heat pumps are turned to full."
Ardern declared a climate emergency in New Zealand in December - something the National Party described as "virtue signalling".