Tuvalu has ratified the Treaty on the Prohibition of Nuclear Weapons, bringing it closer to being in force.
Tuvalu was the 47th nation to make the move, meaning only three more ratifications are needed to empower the treaty.
The treaty establishes a comprehensive ban on the weapons of mass destruction and aims to help pave the way to their elimination.
Earlier this month, Tuvalu and 11 other Pacific small island developing states delivered a joint statement to the UN on the occasion of the International Day for the Total Elimination of Nuclear Weapons.
They noted their region has suffered from the effects of decades of nuclear testing by the United States, the United Kingdom and France.
The 12 nations appealed to all nations that have not yet done so to ratify the Treaty on the Prohibition of Nuclear Weapons, as well as the Comprehensive Nuclear-Test-Ban Treaty of 1996. "We Pacific small island developing states say no to nuclear weapons, and we reiterate our commitment to the elimination of nuclear weapons everywhere."
Tuvalu is the ninth Pacific island nation to join the nuclear weapon ban treaty so far, following Palau, New Zealand, the Cook Islands, Samoa, Vanuatu, Kiribati, Fiji and Niue.
Nauru has signed but not yet ratified the treaty.