New Zealand will give more money and has ratified two international conventions to help fight the global threat of nuclear terrorism.
Prime Minister John Key this morning (local time) addressed the fourth and final Nuclear Security Summit in Washington, where he announced New Zealand would contribute a further $150,000 to US nuclear security programmes in Iraq, Jordan and Cambodia.
Another $148,000 more would go to the International Atomic Energy Agency's Nuclear Security Fund.
New Zealand has now contributed more than $4.6 million towards international nuclear security efforts since the first summit in 2010.
"It's important we continue to support our regional partners through targeted financial contributions," Mr Key said.
He also noted New Zealand last month ratified two important nuclear security conventions: the 2005 Amendment to the Convention on the Physical Protection of Nuclear Material and the International Convention for the Suppression of Acts of Nuclear Terrorism.
Other moves included local law changes to improve the safe handling of radioactive and nuclear materials.
"We will continue to work with other countries to keep nuclear and radioactive materials secure and out of terrorists' hands," Mr Key said.
At the start of the summit US President Barack Obama warned of a persistent threat of terrorists getting their hands on nuclear materials.
"There is no doubt that if these madmen ever got their hands on a nuclear bomb or nuclear material, they would certainly use it to kill as many people as possible."
However, a boycott by Russian President Vladimir Putin, unwilling to join in a US-dominated gathering, has added to doubts that the meeting will yield any major decisions.
Mr Obama said the summits had made significant progress.
Despite that much of the world's plutonium and enriched uranium remained vulnerable to theft.