The obligation to submit declarations and reports
Through the obligation on all states to submit a declaration to the UN Secretary-General within 30 days of becoming party to the TPNW, their status and other resulting positive obligations under the Treaty are formally established.

- Article 2(1) of the TPNW imposes a duty on each state to submit a declaration to the UN Secretary-General within 30 days of becoming party to the Treaty.
- The declaration must clarify whether the state party has ever owned, possessed, or controlled nuclear weapons or other nuclear explosive devices. If it has, it must further declare whether it has already eliminated its nuclear-weapon programme, including by destroying or irreversibly converting all nuclear-weapons-related facilities, or whether it still owns, possesses, or controls any such devices.
- Finally, the declaration must state whether foreign weapons or devices are located – stockpiled, stationed, deployed, or installed – either in its territory or in any other place under its jurisdiction or control.
- Article 4 imposes a duty on all states parties that formerly possessed or currently possess nuclear weapons and all states that have foreign nuclear weapons on their territory or in any place under their jurisdiction or control, to submit a report to each meeting of states parties and each review conference on the progress made towards the
implementation of its obligations under that article, until such time as they are fulfilled.
On the basis of their status, states parties will belong to one of the following four categories:
Non-nuclear-armed states (‘Article 3 states’): These are either states that have never possessed nuclear weapons (the overwhelming majority of potential states parties), or states that relinquished them before the TPNW was adopted on 7 July 2017 (i.e. current states parties South Africa and Kazakhstan, plus Belarus and Ukraine, should they decide to adhere to the Treaty).
Destroy-and-join states (‘Article 4(1) states’): States that possessed nuclear weapons when the TPNW was adopted on 7 July 2017 but which relinquish them before they become a party to the TPNW. This is the ‘destroy-and-join’ pathway for nuclear-armed states’ adherence to the TPNW. At present the nuclear-armed states are China, France, India, Israel, North Korea, Pakistan, Russia, the United Kingdom, and the United States.
Join-and-destroy states (‘Article 4(2) states’): States that still possess nuclear arms when they become party to the TPNW. This is the 'join-and-destroy’ pathway for nuclear-armed states’ adherence to the Treaty. At present, the nuclear-armed states are China, France, India, Israel, North Korea, Pakistan, Russia, the United Kingdom, and the United States.
Host states (‘Article 4(4) states’): States that, when they become party to the TPNW, have nuclear weapons on their territory or in any place under their jurisdiction or control that are owned, possessed, or controlled by another state. At present, the relevant states are Belgium, Germany, Italy, the Netherlands, and Turkey. They would be both Article 3 and Article 4(4) states should they decide to adhere to the Treaty.
Information on the respective obligations that the TPNW lays down on the states in these categories follow in the other sections in the menu.
After the submission of its declaration under Article 2, each state party’s further reporting requirements will depend on its status under the Treaty. All Article 4 states will be required to submit a report to each meeting of states parties and each review conference on the progress made towards the implementation of their obligations under that article, until such time as they are fulfilled.
Work is ongoing with a Model Declaration, to assist the first states parties to the TPNW in preparing it. Since the TPNW enters into force on 22 January 2021, 21 February 2021 is the date upon which the 30-day deadline for submission of a declaration expires for the first 50 states parties. One state had however already provided the requisite declaration. When acceding to the TPNW in September 2018, the Cook Islands declared:
(a) that it does not own, possess, or control nuclear weapons or nuclear explosive devices, nor does it have a nuclear-weapon programme or nuclear-weapons-related facilities in its territory or in any place under its jurisdiction or control;
(b) notwithstanding Article 1(1)(a), that it does not own, possess, or control any nuclear weapons or other nuclear explosive devices;
(c) notwithstanding Article 1(1)(g), that there are no nuclear weapons or other nuclear explosive devices in its territory or in any place under its jurisdiction or control that are owned, possessed, or controlled by another state.
The Cook Islands has thereby complied with all of its obligations under Article 2 of the TPNW.
In addition to the declarations required by Article 2 and reporting required by Article 4, the Nuclear Weapons Ban Monitor would encourage voluntary reporting under the TPNW on legislative and other measures taken to implement the Treaty (Article 5) and on other issues such as cooperation and assistance, victim assistance, and environmental remediation.