Obama says threat of nuclear weapons remains

SEOUL, South Korea (AP) -- President Barack Obama said Tuesday the threat of nuclear weapons remains a potent challenge for the globe to confront, telling foreign leaders that "the security of the world depends on the actions that we take."

Obama, speaking at a nuclear security summit in South Korea, said the international community had made progress in removing nuclear materials and improving security at nuclear facilities around the globe. As a result, he said more of the world's nuclear materials won't fall into the hands of terrorists.

But the president warned "there are still too many bad actors in search of these dangerous materials and these dangerous materials are still vulnerable in too many places."

"It would not take much, just a handful or so of these materials, to kill hundreds of thousands of innocent people and that's not an exaggeration, that's the reality that we face," Obama said. Read More