NNSA is responsible for providing key technical and policy support to the U.S. government's negotiating efforts within the multilateral nuclear export control regimes, the Nuclear Suppliers Group  (NSG) and the Treaty on the Nonproliferation of Nuclear Weapons  (NPT) Exporters Committee or (Zangger Committee  ).
The NSG is a group of nuclear supplier countries that seek to contribute to the nonproliferation of nuclear weapons through the implementation of agreed conditions of supply (guidelines) and control lists for nuclear and nuclear-related dual-use items and technologies. NSG members implement the guidelines and lists of controlled items and technologies in line with national laws and policies. Currently, there are 45 NSG members.
The Zangger Committee is primarily responsible for interpreting Article 3.2 of the NPT and the meaning of "especially designed or prepared" equipment or material for the processing, use or production of special fissionable material. The Zangger Committee maintains a Trigger List (triggering safeguards as a condition of supply) of nuclear items to assist NPT Parties in identifying equipment and materials subject to export controls. There are 35 Zangger members.
As a founding member of both regimes, the U.S. has been a key contributor to the efforts to strengthen the NSG and the Zangger Committee since their inception. NNSA's Nuclear Supply and Transfers Team, along with U.S. national laboratory representatives, have been viewed as the core technical nuclear experts at regime meetings and international negotiations. NNSA has initiated and contributed to a number of changes to help strengthen the NSG and the Zangger Committee over time and have led various efforts within the regimes to make the controls, guidelines, and outreach efforts more effective.
NNSA contributed to U.S. government's effort in the NSG to negotiate measures that would help restrict further transfers of the most sensitive nuclear technologies, to recognize the importance of the International Atomic Energy Agency  Additional Protocol, and to implement measures that will bring supplier states together to consider how to address nuclear cooperation, including the possibility for suspension of nuclear trade with countries that violate safeguard obligations.