UN Secretary-General Antonio Guterres has warned the political will to fight climate change seems to be fading at the same time as things are getting worse for those on the front-line.

Mr Guterres made the comments after arriving in New Zealand, where he spoke alongside Prime Minister Jacinda Ardern in Auckland.

Mr Guterres plans to spend three days in New Zealand as part of a trip to the South Pacific to highlight the problems of climate change.

In Christchurch, he will also meet with Muslim leaders following the March 15 killing of 51 worshippers by a gunman who attacked two mosques during Friday prayers.

Mr Guterres said he usually visits a Muslim country during the holy month of Ramadan but this year decided to visit Muslims in New Zealand as a tribute to their courage and resilience after the attack.

On climate change, he said countries are not living up to their commitments under the 2016 Paris Agreement to keep the global temperature rise to below 2C above pre-industrial levels.

He said: “We are not on track to achieve the objectives defined in the Paris Agreement.

“And the paradox is that as things are getting worse on the ground, political will seems to be fading.”

He commended Ms Ardern for last week introducing an ambitious Bill that aims to make New Zealand mostly carbon neutral by 2050.

Antonio GuterresMr Guterres said nations must meet commitments made in the Paris Agreement (Mary Altaffer/AP)

Mr Guterres said Pacific Island nations are on the front-line of climate change.

“We cannot allow for runaway climate change,” he said. “We need to protect the lives of our people and we need to protect our planet.”

He will also visit Fiji, Tuvalu and Vanuatu during his visit, and meet leaders and senior government officials from the Pacific Islands Forum.

His trip comes ahead of the Climate Action Summit that he plans to convene in September in New York.