Sri Lanka
Sri Lanka acceded to the Treaty on the Prohibition of Nuclear Weapons (TPNW) on 19 September 2023. The then-Minister of Foreign Affairs, M. U. M. Ali Sabry, deposited the instrument of accession with the UN Secretary-General at a high-level ceremony in New York, describing it as a reaffirmation of Sri Lanka’s ‘long-standing commitment towards nuclear disarmament in favour of international peace and security’.1
TPNW Status
| Key weapons of mass destruction treaties | ||
|---|---|---|
| NUCLEAR WEAPONS | ||
| Party to the TPNW | Yes (Acceded 2023) | |
| Party to the NPT | Yes (Ratified 1979) | |
| Ratified the CTBT | Yes (Ratified 2023) | |
| Party to an NWFZ | No | |
| CSA with the IAEA | Yes (In force 1984) | |
| AP with the IAEA | No (Approved 2018) | |
| BIOLOGICAL AND CHEMICAL WEAPONS | ||
| Party to the BWC | Yes (Ratified 1976) | |
| Party to the CWC | Yes (Ratified 1994) | |
| TPNW Art. 1(1) prohibitions: Compliance in 2024 | ||
|---|---|---|
| (a) | Develop, produce, manufacture, acquire | Compliant |
| Possess or stockpile | Compliant | |
| Test | Compliant | |
| (b) | Transfer | Compliant |
| (c) | Receive transfer or control | Compliant |
| (d) | Use | Compliant |
| Threaten to use | Compliant | |
| (e) | Assist, encourage or induce | Compliant |
| (f) | Seek or receive assistance | Compliant |
| (g) | Allow stationing, installation, deployment | Compliant |
| TPNW voting and participation | |
|---|---|
| UNGA resolution on TPNW (latest vote) | Voted yes (2025) |
| Participated in 2MSP (2023) | Yes (observer) |
| Participated in 1MSP (2022) | No |
| Average MSP delegation size (% women) | 4 (50%) |
| Adoption of TPNW (7 July 2017) | Voted yes |
| Participated in TPNW negotiations (2017) | Yes |
| Negotiation mandate (A/RES/71/258) | Voted yes |
| Fissile material | |
|---|---|
| Nuclear facilities | No |
| Fissile material production | No |
| HEU stocks | No |
| Plutonium stocks | No |
| SQP with the IAEA | No |
Latest developments
At the Third Meeting of States Parties (3MSP) to the Treaty on the Prohibition of Nuclear Weapons (TPNW) in March 2025, Sri Lanka said: ‘Given the rising tensions between nuclear powers, the [TPNW] has never been more important—it acts as a lodestar, guiding our collective efforts towards the complete elimination of nuclear weapons, which cause such horrors.’2
In the Conference on Disarmament in February 2025, the Minister of Foreign Affairs of Sri Lanka, Vijitha Herath, said that his country’s accession to the TPNW in 2023 and its ratification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) the same year are ‘demonstrations of its long-standing commitment to and advocacy of nuclear disarmament, which date back to the 1960s’.3
At the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) Preparatory Committee meeting in May 2025, Sri Lanka said that its accession to the TPNW in 2023 ‘reflects our firm belief that the TPNW complements the NPT by reinforcing its disarmament pillar and advancing international norms’. ‘The continued existence of nuclear weapons is not a sign of strength—it is a threat to our shared future, a gamble with the lives of both present and future generations,’ it said.4
At a high-level event on 26 September 2025 marking the International Day for the Total Elimination of Nuclear Weapons, Sri Lanka reaffirmed its commitment to the NPT and the TPNW. ‘We view these instruments as important tools in our collective effort to achieve a world free of nuclear weapons,’ it said.5
In the First Committee of the UN General Assembly in October 2025, Sri Lanka described nuclear weapons as an ‘existential danger’ and lamented the growing risk of their use. It also expressed pride in being a State Party to the TPNW, the NPT, and the CTBT.6
Sri Lanka co-sponsored the 2025 UN General Assembly resolution on the TPNW, which welcomed the Treaty’s entry into force and called upon ‘all States that have not yet done so to sign, ratify, accept, approve, or accede to the Treaty at the earliest possible date’.7
Recommendations
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Sri Lanka should encourage other states to adhere to the TPNW:
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Sri Lanka should ensure that all the TPNW obligations are implemented domestically, through legal, administrative, and other necessary measures.
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Sri Lanka should bring into force its Additional Protocol (AP) with the International Atomic Energy Agency (IAEA).