One of the most urgent challenges facing the International Atomic Energy Agency (IAEA) is to strengthen the Agency’s safeguards system for verification in order to increase the likelihood of detecting any clandestine nuclear weapons programme in breach of international obligations. The IAEA should be able to provide credible assurance not only about declared nuclear material in a State but also about the absence of undeclared material and activities. Realising the full potential of the strengthened system will require that all States bring into force their relevant safeguards agreements, as well as additional protocols thereto.