TONGA has ratified the Comprehensive Nuclear-Test-Ban Treaty, becoming the 179th country to do so and completing treaty universalisation across the Pacific region.
The ratification was formalised at a ceremony at U.N. headquarters in New York, where Tonga’s U.N. ambassador, Viliami Va’inga Tōnē, deposited the instrument of ratification, according to the CTBTO.
Tōnē said the move carried symbolic weight for a region long affected by nuclear testing.
“For Tonga, this is not simply a legal formality. It is a statement of who we are and what we stand for,” he said.
“The Pacific has felt the pain of nuclear testing. Ratifying CTBT is our contribution to ensuring that no one, anywhere, has to go through that again.”
CTBTO Executive Secretary Robert Floyd said in a statement, “Tonga’s ratification is a proud moment for the Pacific and a meaningful contribution to the global effort to ban nuclear test explosions for good.
“The Kingdom has long stood on the right side of this issue.”
United Nations High Representative for Disarmament Affairs Izumi Nakamitsu said the treaty remains central to the global non-proliferation system.
“The CTBT is an integral part of the global disarmament and non-proliferation architecture,” she said.
“It embodies a simple but vital truth: nuclear tests must never be allowed – not even one.”
CTBT bans all nuclear explosions everywhere. It has 188 signatories and 179 ratifying states, but it has not yet entered into force because ratification is required by all 44 states listed in Annex 2.
CTBTO said nine Annex 2 ratifications were still needed. The nine are: Russia, China, Egypt, Iran, Israel, the United States, India, North Korea, and Pakistan.
Tonga is party to the Treaty of Rarotonga, which created the South Pacific Nuclear-Free Zone, and is also a state party to the Nuclear Non-Proliferation Treaty.
The organisation said the ratification follows years of engagement with Tongan leaders and regional partners, including meetings between Floyd and senior Tongan officials in 2025 and 2026.
