The world’s first-ever treaty regulating the $70 billion global arms trade has moved a step closer to taking effect. On Wednesday, 18 United Nations member states ratified the measure, bringing the total number of ratifications to 31 — 19 short of the 50 needed for it to enter force. Anna MacDonald of the Control Arms Coalition urged the remaining holdouts to sign on.

Anna MacDonald: “You now have the opportunity to lead by example. All governments are responsible for the arms trade, and all governments need to act to ensure it is brought under control. States must now rigorously asses all arms and ammunition transfers, whether they are leaving, entering or passing through their territory. They must apply the treaty’s criteria robustly and deny arms transfers where there is a substantial risk that they will be used for violations of human rights and humanitarian law, including gender-based violence.”

The measure regulates the sale of conventional weaponry, including tanks and guns, in a bid to prevent acts of genocide or terrorism. The United States is the world’s largest weapons exporter. It signed the treaty last year, but has not yet ratified it over opposition in the Senate.