New Zealand will become one of the first countries to sign a global Treaty on the Prohibition of Nuclear Weapons in New York this week.
Foreign Minister Gerry Brownlee says the nation will sign up to the treaty on September 20, the first day it opens for signatures.
"Our signing at this first opportunity is consistent with New Zealand's long-standing commitment to international nuclear disarmament efforts," Mr Brownlee said.
"While no state currently in possession of nuclear weapons will be signing along with us, this Treaty nevertheless represents an important step towards a nuclear-free world."
New Zealand and 120 other countries backed the adoption of the treaty at a United Nations conference in July.
It will come into force when it has been ratified by 50 states.