New Zealand's foreign minister Nanaia Mahuta is launching a new strategy during her visit to Tonga, which outlines how decisions will be made to spend the $1.3 billion New Zealand pledged for climate finance ahead of last year's UN Climate Change Conference (COP26).

The Aotearoa New Zealand International Climate Finance Strategy, Tuia te Waka a Kiwa, was released by Mahuta and Climate Change Minister James Shaw this morning.

It would spell out in practical terms how New Zealand could put its investments to work "to support Pacific partners and whānau to build resilience and deal with the number one security threat in the region," Mahuta said.

In announcing the $1.3bn climate finance pledge last year, Shaw said at least half of the money would go to the Pacific.

Mahuta, who has visited both Niue and Tonga this week, said yesterday that climate change was "the existential challenge in the Pacific" and addressing it was the main purpose of her trip.

A speech Mahuta was set to deliver in Nuku'alofa today, said the new strategy had four key goals: to enhance resilience and adaptation to the impacts of climate change; to promote quicker action on mitigation measures; to improve information to allow evidence-based decision-making; and to leverage investments to make a greater climate impact.

"We recognise the importance of local solutions," her speech said, adding that many communities had been adapting to changes in their environments for decades.

"We are committed to supporting indigenous-led climate projects and working with communities in ways that recognise their history, culture and expertise."

Mahuta also announced today that the first investment under the new strategy would be a contribution of NZ$8 million to Tonga's Climate Change Fund, which was established to receive and direct investments towards mitigation and adaptation projects.

Shaw said the Tuia te Waka a Kiwa strategy underlined New Zealand's commitment to climate action in the Pacific.

"Our Pacific Island neighbours are amongst the most at risk from sea level rise, storms and warming oceans, which are all symptoms of the climate crisis. Yet they bear very little responsibility for causing the climate crisis in the first place," he said.

"The strategy we are announcing today will help build to a resilient, prosperous future for Pacific Islands."