President Joe Biden has announced that the United States has fully destroyed its decades-old stockpiles of chemical weapons, fulfilling a commitment under the three-decade-old Chemical Weapons Convention.
"Today, I am proud to announce that the United States has safely destroyed the final munition in that stockpile — bringing us one step closer to a world free from the horrors of chemical weapons," Biden said on Friday.
The United States was the last of the Chemical Weapons Convention's signatories to complete the task of destroying their "declared" stockpiles, though some are believed to maintain secret reserves of chemical weapons.
"It marks the first time an international body has verified destruction of an entire category of declared weapons of mass destruction," Biden said in a statement.
The announcement came after the Blue Grass Army Depot, a US Army facility in Kentucky, recently completed its four-year job of eliminating some 500 tonnes of lethal chemical agents, the last batch held by the US military.
The US had held for decades stores of artillery projectiles and rockets that contained mustard gases, VX and sarin nerve agents, and blister agents.
Such weapons were condemned widely after their use with horrendous results on the battlefields of World War I.
But many countries retained and further developed them in the years afterwards.
70,000 tonnes of poisons
The Chemical Weapons Convention, agreed in 1993 and coming into effect in 1997, gave the United States until September 30 this year to destroy all of its chemical agents and munitions.
Other signatories to the pact had already eliminated their holdings, Fernando Arias, head of the Organization for the Prohibition of Chemical Weapons [OPCW], said in May.
That left only the United States to complete the task, he said.
"More than 70,000 tonnes of the world's most dangerous poisons have been destroyed under the supervision of the OPCW," he said.
According to the US Arms Control Association, in 1990, the United States held nearly 28,600 tonnes of chemical weapons, the world's second-largest store after Russia.
With the ebb of the Cold War, the superpowers and other countries joined together to negotiate the Chemical Weapons Convention.
Eliminating the stockpiles, doubly dangerous because it means neutralising not only the chemical agents but also the munitions they are contained in, was a slow process.
Russia completed destroying its own declared stockpiles in 2017.
By April 2022, the US had less than 600 tonnes left to destroy.
Biden urged continued vigilance to ensure all chemical weapons around the world are destroyed and said that the handful of countries that have not joined the convention should do so.
"Russia and Syria should return to compliance with the Chemical Weapons Convention and admit their undeclared programmes, which have been used to commit brazen atrocities and attacks," Biden said.
According to the United Nations, chemical weapons killed nearly 100,000 people during World War One and have caused more than 1 million casualties around the world since then.