Ms Nuku said the NZNO first identified the pay gap through a survey in 2007 and presented the findings to a government select committee in 2008.
The committee called on the Government to address the inequity as a matter of urgency.
"After decades of nursing why is Maori nurses' work still not being properly recognised?
"We have been trying for a long time to get government action but it seems nothing is going to be actively done about it."
The UN Permanent Forum seemed "a logical approach to the problem" because it affected indigenous nurses.
She said her presentation was well received and she hoped the forum would go back to the Government here to seek answers or evidence of progress.
New Zealand's Maori population was ageing and had high levels of complicated health conditions, for which government agency Health Workforce New Zealand said there needed to be a tripled Maori workforce by 2035.
Maori are 7 per cent of the nursing workforce of 53,000 and 27 per cent had overseas qualifications "so there is quite a gap".
She said it was difficult for the NZNO to gain traction for collective representation because of the wide geographical spread of Maori nurses.
There might be only one or two nurses working for a health provider "so it is very difficult to generate momentum and density of voice".
"Historically, we were only trained to work in the community, with our people, not in hospitals."
She said Maori health professional body Te Poari has lodged a complaint with the New Zealand Human Rights Commission over the pay gap and was considering whether it was also a Treaty of Waitangi breach.