The first treaty to ban nuclear weapons is ready for countries to sign at the United Nations. It's backed by over 100 countries, but nuclear-armed nations want no part of it.
U.N. Secretary-General Antonio Guterres opened a signing ceremony Wednesday. He called the pact "an important step towards the universally-held goal of a world free of nuclear weapons."
More than 120 countries approved the treaty in July over strong opposition from nuclear-armed countries and their allies. They boycotted negotiations.
Supporters of the pact say it's time to push harder toward eliminating atomic weapons than nations have done through the nearly 50-year-old Nuclear Non-Proliferation Treaty.
But nuclear powers say a ban won't work. French Foreign Minister Jean-Yves Le Drian said Monday it can only weaken the nonproliferation treaty.