The International Red Cross and Red Crescent Movement on Friday welcomed the entry into force of the first instrument of international humanitarian law to include provisions to help address the catastrophic humanitarian consequences of using and testing nuclear weapons.

The United Nations announced Saturday that 50 countries have ratified a U.N. treaty to ban nuclear weapons triggering its entry into force in 90 days, a move hailed by anti-nuclear activists but strongly opposed by the United States and the other major nuclear powers.