St Lucia has become a party to the Treaty on the Prohibition of Nuclear Weapons, the 20th state to do so since it was agreed by the United Nations.

St Lucia could not officially ratify the Treaty as many others have done, because it did not take part in the negotiations in 2017. It becomes the fifth state from the Association of Caribbean States to become a party to the Treaty following Cuba, Costa Rica, Guyana and Nicaragua.

The Treaty will ban nuclear weapons in the same way as chemical and biological weapons have previously been banned, mainly due to their catastrophic humanitarian consequences. These were shown starkly in both Hiroshima and Nagasaki.

The Treaty will come into force once 30 more states become party to the Treaty, expected to be sometime in the next 18 months.