More than 50 heads of state and international organizations are expected to attend the March 26-27 summit. In what will be South Korea's largest international conference, the summit will facilitate discussions on the prevention of nuclear terrorism as well as safety in the aftermath of last year's Fukushima disaster in Japan.
The inaugural summit was held in Washington by President Barack Obama in 2010.
"The number of assistants helping out at the event will reach about 800," one event organizer told Yonhap News Agency. "We are doing our best to ensure the event is carried off flawlessly, as even a minor mistake could turn into a diplomatic faux pas."