Fissile materials are materials that can undergo the fission reaction. They are the key component of nuclear weapons or other nuclear explosive devices. Those mostly used in nuclear weapons are highly enriched uranium (U-235 isotope of uranium) and plutonium (Pu-239 isotope of plutonium).

A non-discriminatory, multilateral and internationally and effectively verifiable treaty banning the production of fissile material for nuclear weapons or other nuclear explosive devices would strengthen the nuclear non-proliferation regime and might represent a practical contribution to the nuclear disarmament efforts.

The issue has been under discussion for many years in the Conference on Disarmament (CD) . In 1995, the CD adopted the report (CD/1299) of the Special Coordinator, Ambassador Shannon of Canada, on the outcome of his consultations “on the most appropriate arrangement to negotiate a treaty banning the production of fissile material for nuclear weapons or other nuclear explosive devices”. The report also contained a mandate for the establishment of an ad hoc committee on a “ban on the production of fissile material for nuclear weapons or other nuclear explosive devices”. Substantive negotiations, however, never started.

In an attempt to overcome the political stalemate in the CD, several initiatives have also taken place. In 2012, the United Nations General Assembly adopted resolution 67/53 by which it requested the Secretary-General “to seek the views of Member States on a treaty banning the production of fissile material for nuclear weapons or other nuclear explosive devices, including possible aspects thereof, and to submit a report(A/68/154) (A/68/154/Add.1) on the subject to the General Assembly at its sixty-eighth session”. The resolution also established a group of governmental experts, which in its final report submitted to the United Nations General Assembly made recommendations on possible aspects that could contribute to but not negotiate a treaty banning the production of fissile material for nuclear weapons or other nuclear explosive devices on the basis of document CD/1299 and the mandate contained therein. Member States subsequently submitted their views on this final report.

In 2016, the UN General Assembly adopted resolution 71/259 by which the Secretary-General was requested to establish a “high-level fissile material cut-off treaty (FMCT) expert preparatory group“. The group was mandated to consider and make recommendations on substantial elements of a future non-discriminatory, multilateral and internationally and effectively verifiable treaty banning the production of fissile material for nuclear weapons or other nuclear explosive devices, on the basis of CD/1299 and the mandate contained therein. The group also examined the report of the Group of Governmental Experts with a view to making possible recommendations and agreed on a final report that was submitted to the United Nations General Assembly.

Specific projects aimed at supporting this process and increase the understanding and engagement of more UN Member States into an informal, open-ended consultative process, were also initiated by Canada and by the European Union.