President Joe Biden has announced that the United States has successfully eradicated its last known chemical weapons stockpile, marking the end of a warfare chapter initiated during World War I.

On Friday, Kentucky’s Blue Grass Army Depot workers achieved this by demolishing rockets containing GB nerve agent or sarin. This effort was the final stage of a multi-decade campaign to obliterate a stockpile amassing over 30,000 tonnes by the end of the Cold War.

Biden acknowledged this milestone in a White House statement, saying it takes us “one step closer to a world free from the horrors of chemical weapons” and expressed gratitude to the countless Americans who dedicated their skills to this noble cause for over three decades.

Mitch McConnell, the Republican Senate minority leader, also expressed appreciation for the landmark achievement, acknowledging the widespread destruction caused by chemical weapons throughout history. McConnell reiterated in a statement, “Though the use of these deadly agents will always be a stain on history, today our nation has finally fulfilled our promise to rid our arsenal of this evil.”

The US had until September 30 to eliminate its remaining chemical weapons under the International Chemical Weapons Convention. This treaty, effective since 1997, has 193 member countries.

Kingston Reif, an assistant US secretary of defense for threat reduction and arms control, referred to the destruction of the last US chemical weapon as the closure of an “important chapter in military history.”