The government will spend $2 million over the next three years to begin making the sub-Antarctic Auckland Island pest free.
Speaking at Forest and Bird's 2018 Conference, Conservation Minister Eugenie Sage said the money would be spent on planning, including field trials.
Ms Sage said ridding the 46 thousand hectare island of predators was an ambitious project.
"The funding will allow greater understanding of the scale and complexity of the problem and help guide decisions about eradicating pigs, cats and mice from Auckland Island."
Early estimates suggested the potential cost of eradication could be $40 to $50 million over eight to 10 years, she said in a statement.
Auckland Island is the main island of the sub-Antarctic Auckland Islands, and is the largest and biologically richest archipelago of the five island groups that make up New Zealand's sub-Antarctic islands.
The $2m feasibility funding comes from the Budget 2018 pest control four-year appropriation of $81.3m aimed towards achieving a predator free New Zealand by 2050.
Introduced pigs and cats had devastated native wildlife and plants on New Zealand's fifth-largest island and mice were also a huge problem, Ms Sage said.
Eradicating those pests would see Auckland Island become the country's largest pest-free island.