This past June, the UN published the final report of the Group of Governmental Experts to Further Consider Nuclear Disarmament Verification Issues

the Group developed the following working definition to guide its work: nuclear disarmament verification is a process driven by states parties to a specific treaty, agreement or arrangement, of gathering and analysing information, based on agreed technologies, methodologies and procedures, to enable assessment of compliance with relevant nuclear disarmament commitments and obligations, or an assessment of adherence to unilateral undertakings as set out in a verification arrangement, with the overarching goal of achieving and maintaining a world free of nuclear weapons.