John Key is in Washington this weekend, pushing for tighter controls to stop terrorists getting hold of nuclear material.
The Prime Minister this morning said even though New Zealand has no nuclear weapons or nuclear power, it was important the small amount of radioactive matter used in medicine was properly monitored.
Mr Key told Newstalk ZB that New Zealand's nuclear-free status carried some weight at the Nuclear Security Summit in the American capital today.
The summit, which was first held in 2010, is an international effort to combat the threat of nuclear terrorism.
Member states have worked together to secure vulnerable nuclear materials, break up black markets, and put measures in place to detect and intercept illicitly trafficked materials.
In a statement, Mr Key said New Zealand was playing its part to ensure the threat of global nuclear terrorism was never realised.
"Although New Zealand is geographically isolated and has only small amounts of radioactive and nuclear material, this alone does not guarantee our security," said Mr Key.
"We take our responsibility of ensuring these materials are safeguarded in our country very seriously."
Mr Key announced New Zealand's ratification of two major nuclear security conventions at the summit today -- an amendment to the Convention on the Physical Protection of Nuclear Material, and the International Convention for the Suppression of Acts of Nuclear Terrorism.
These conventions place obligations on countries to protect nuclear material and enhance co-operation to combat nuclear terrorism.
Mr Key also announced New Zealand would contribute a further $150,000 to United States nuclear security programmes in Iraq, Jordan and Cambodia and an additional $148,000 to the International Atomic Energy Agency's Nuclear Security Fund.
"Since the first Nuclear Security Summit in 2010, New Zealand has contributed more than $4 million to international projects to strengthen nuclear security.
"It's important we continue to support our regional partners through targeted financial contributions."
Mr Key said New Zealand had taken a number of steps to help with the global effort to ensure nuclear and radioactive materials were kept secure.
"The Radiation Safety Act 2016, which was passed earlier this year, provides new regulations for people who use or manage radioactive or nuclear material.
"Last November the International Atomic Energy Agency reviewed New Zealand's national security regime for radioactive material, and commended New Zealand for its proactive approach to these issues and noted that our new legislative framework supports international best practice on nuclear security.
"We will continue to work with other countries to keep nuclear and radioactive materials secure and out of terrorists' hands."
This year's summit was the fourth and final one, but participating countries have agreed to continue working together in this area.