TPNW First Meeting of States Parties

The First Meeting of States Parties (1MSP) to the Treaty on the Prohibition of Nuclear Weapons (TPNW) took place in Vienna, Austria, from 21–23 June 2022, under the presidency of Austrian diplomat Alexander Kmentt. It was the first formal gathering of governments bound by the TPNW since the treaty entered into force on 22 January 2021, having reached the threshold of 50 ratifications in October 2020.

The meeting produced two principal outcome documents: the Vienna Declaration ("Our Commitment to a World Free of Nuclear Weapons") and the Vienna Action Plan, a 50-point roadmap covering universalization, victim assistance, environmental remediation, and the establishment of scientific advisory mechanisms. Delegates adopted deadlines for nuclear-armed states that might later join: 10 years to eliminate their arsenals and 90 days to remove any nuclear weapons hosted on their territory.

Notably, several NATO members — including Germany, Norway, the Netherlands, Belgium, and Australia — attended as observers despite their alliance commitments and U.S. nuclear-sharing arrangements. No nuclear-weapon state participated. The meeting was preceded by the Vienna Conference on the Humanitarian Impact of Nuclear Weapons (20 June 2022) and an ICAN civil society forum, continuing the "humanitarian initiative" framing that drove the treaty's negotiation.

Key institutional decisions included:

• Creating an informal working group on victim assistance and environmental remediation, co-chaired by Kazakhstan and Kiribati.
• Establishing a scientific advisory group of 15 experts on nuclear weapons risks and disarmament verification.
• Tasking a working group on the treaty's complementarity with the NPT and other instruments.

The 1MSP took place against the backdrop of Russia's invasion of Ukraine and explicit Russian nuclear threats, which the Vienna Declaration condemned without naming Moscow directly. The Second Meeting of States Parties (2MSP) followed at UN Headquarters in New York from 27 November–1 December 2023, chaired by Mexico.