Atomic scientists on Tuesday moved their "Doomsday Clock" closer to midnight than ever before, citing Russian nuclear threats amid its invasion of Ukraine, tensions in other world hot spots, military applications of artificial intelligence and climate change as factors underlying the risks of global catastrophe.

The Bulletin of the Atomic Scientists said the United States, China and Russia have the prime responsibility to pull the world back from the brink.

Bulletin of the Atomic Scientists says the United States, China and Russia have the prime responsibility to pull the world back from the brink