The Government has injected $28 million into the battle to save New Zealand's iconic kauri from an as yet uncurable tree-killing disease.

Kauri dieback disease has become prominent over the past decade, spreading throughout the Auckland region and the Coromandel, to Waipoua Forest in Northland and most recently Puketi Forest in the Bay of Islands.

Last month, an expert warned other tree species could be lost if the soil-borne disease wasn't stopped.

Today's Budget announcements include $28m, as part of $32m in funding over five years, to roll out a new National Pest Management Plan to protect kauri.

Biosecurity Minister Damien O'Connor said this was the strongest form of protection available under the Biosecurity Act 1993 to combat the disease.

"It is a legal framework that will bring together the work of Government, councils, iwi and non-government organisations under a new umbrella agency that will oversee all activity regarding the spread of kauri dieback," he said.

"It ensures everyone is at the decision-making table and involved in the strategic direction and day-to-day response."

There is currently no proven cure or treatment and nearly all infected kauri die. The disease is easily spread through soil movements, for example, when soil is carried on dirty footwear, animals, equipment and vehicles.

Associate Environment Minister James Shaw described kauri as an "incredibly important taonga for Aotearoa New Zealand".

"Today's announcement builds on the work of existing kauri programmes and will help to contain the disease while a cure is found."

University of Auckland ecologist Associate Professor Cate Macinnis-Ng said one of the biggest challenges facing scientists was understanding at what point a tree became infected.

"We are still just testing the soil, which is not necessarily a good indication that a tree is infected, so we can't really pinpoint where within a forest infection is occurring," she said.

"There is a lot of positive work being done by the Kauri Rescue Group, in terms of using treatments to look after infected trees.

"But will it be possible to stop trees being infected? Obviously that would be the ultimate, and we're still working on that."

Macinnis-Ng added that scientists working in the Ngā Rakau Taketake programme, which fell under the Biological Heritage National Science Challenge and targeted kauri dieback as well as myrtle rust, were also making good progress.

"So there's definitely some really great work happening, but the more funding, the better, because they're such massive challenges."

Forest and Bird was underwhelmed at the new funding, which it considered just a third of what was needed.

"$8m per year, declining to only $4m in 2024, isn't enough to bring back the health of our northern forests, or protect our still healthy kauri," the advocacy group tweeted.

"This is Tane Mahuta we're talking about," it said, referring to the Waipoua Forest's famed resident kauri.

Auckland Council has just launched a full health check of more than 3000 kauri, which will be monitored over the next few years.

Associate Professor Bruce Burns, from the School of Biological Sciences at the University of Auckland, told RNZ other native species could also be lost if kauri dieback was not stopped.

"It almost selects the species that live with it and so if we take kauri out of the system then all those species that are dependent on it will also be lost," he said.

"The opportunity to eradicate the disease has well and truly passed, so this is more about how we can focus on reducing the spread of the disease, but also how we can reduce the impact where the disease is."