As of Friday, the treaty had 49 signatories, and the United Nations said the 50th ratification from Honduras had been received.

The U.S. State Department has accused China of triggering low-level nuclear blasts at a subterranean site without providing evidence.

Russia says the image proves the U.S. was violating a Cold War-era nuclear arms treaty two years before the Trump administration announced it was withdrawing from the agreement.

Russia will abandon a centerpiece nuclear arms treaty but will only deploy intermediate-range nuclear missiles if Washington does so, President Vladimir Putin said.

Setsuko Thurlow was 13 when the 1945 bombing devastated her Japanese city.

More than 120 countries have approved the first-ever treaty banning nuclear weapons at a U.N. meeting boycotted by all nuclear-armed nations.