Jacinda Ardern says the veto power wielded by the five permanent members of the United Nations Security Council has made a "mockery of what the UN stands for".
Ms Ardern is off to New York this weekend for the General Assembly, where she'll deliver the keynote address at the opening of UN Climate Week. She'll also be speaking at other climate-themed events, appear on The Late Show with Stephen Colbert and CNN, and meet Hollywood actress Anne Hathaway, a UN Women Goodwill Ambassador.
On Thursday (New York time) she'll deliver New Zealand's statement in the UN general debate, during which she's expected to touch on the Security Council's inability to deal with conflicts raging around the globe.
"UN reform, rightly, needs to be high on the agenda," Ms Ardern told Newshub Nation on Saturday.
New Zealand has long argued against the veto powers, held by France, the UK, the United States, Russia and China, which can block action being taken when it interferes with one or more of the major powers' geopolitical goals.
Previous Foreign Minister Murray McCully railed against the veto, calling the Security Council "dysfunctional" because of it. France has called for the veto to be waived in cases of mass atrocities.
Ms Ardern said New Zealand has been "utterly consistent" on the veto, regardless of who is in Government.
"We think that they should no longer be used. They should be gone. In our view, it makes a mockery of what the UN stands for and the way that it tries to build that general consensus around issues of international importance."
She said if the veto powers can't be revoked, France's suggestion would be a good consolation prize.
"As a secondary option to getting rid of the veto altogether, we support that, and we will continue to advocate for that."