South Korea is preparing to host the heads of more than 50 nations and international organisations at a nuclear security summit in Seoul.
The meeting, starting on Monday, comes a year after the meltdown at the Fukushima nuclear plant in Japan and participants will discuss efforts to stop the spread of nuclear weapons and how to restore faith in civil nuclear energy.
Participants include US President Barack Obama, who is due to visit the border zone between the two Koreas on Sunday, and Chinese President Hu Jintao.
The controversial nuclear programmes of North Korea and Iran are not due to be formally discussed.
But Obama is expected to hold talks on the sidelines with both Hu and South Korean President Lee Myung-Bak over North Korea's plans to launch a satellite into space aboard a long-range rocket next month.
Dozens of protesters from South Korea, Japan, Taiwan and Thailand gathered near the summit venue in downtown Seoul on Friday to denounce the gathering, saying nuclear energy was threatening the safety of their lives.
"The nuclear energy industry told us the industry is safe, but actually, there have been many accidents that happened," Lee Heonseok, a protester, said.
"We think those accidents will be repeated in the future. Therefore, we insist the nuclear energy industry should disappear."
Richard Broinowski, a professor at the University of Sydney and former Australian ambassador to South Korea, told Al Jazeera that the summit was aimed at rebuilding confidence in the nuclear industry.
"The point of the safety nuclear conference should be about terrorism and the breakdown of systems, such as what happened in Fukushima, and what to do about them," he said.
But the summit could be overshadowed by diplomatic fallout from North Korea's announcement of its planned rocket launch.
North Korea said earlier this month that it had halted its nuclear programme, weapons testing and long-range missile launches and was ready to return to international talks in return for US food aid.
The US says April's rocket launch would violate that agreement, while Japan's defence minister said on Friday he had ordered the military to prepare to shoot down the rocket if it entered Japanese airspace.
China, North Korea's closest regional, has also expressed concern that the launch could endanger regional stability.