World leaders gathered at the Nuclear Security Summit in Washington pose for a photo opportunity on the first day of a global nuclear security meeting convened by U.S. President Barack Obama. Rough Cut (no reporter narration).
ROUGH CUT (NO REPORTER NARRATION) STORY: World leaders who were gathered at the Nuclear Security Summit in Washington posed for a photo opportunity on Friday (April 1), the first day of a global nuclear security meeting convened by U.S. President Barack Obama. Obama is hosting more than 50 world leaders for his fourth and final summit focused on efforts to lock down vulnerable atomic materials to prevent nuclear terrorism. North Korea's nuclear defiance was also high on the agenda. He has less than 10 months left in office to follow through on one of his signature foreign policy initiatives. While progress has been made, many arms-control advocates say the diplomatic process - which Obama conceived and championed - has lost momentum and could slow even further once he leaves the White House in January.