South Korea's foreign minister said Monday that the question of how to strengthen global atomic safety following Japan's nuclear disaster would be a key topic at an upcoming summit in Seoul.

Kim Sung-Hwan said the Fukushima disaster highlighted the vulnerability of nuclear power plants and the extent of damage that could be caused by a terrorist attack against a nuclear plant.

The Fukushima nuclear crisis was sparked by a huge earthquake and tsunami on March 11 last year, that devastated Japan's northeast coast and left more than 19,000 people dead.

"As seen in the Fukushima nuclear accident, public fear of radiation exposure causes significant and lasting social and cultural concern," he told reporters.

"A similar impact could be seen if terrorists attack a nuclear facility," he said, adding the March 26-27 Nuclear Security Summit would help world leaders work out measures to prevent such disasters.

The summit will be the largest ever staged by South Korea in terms of the number of global leaders expected. Organisers say about 40 heads of state or government including US President Barack Obama will take part in the summit.

The summit, a follow-up to one in Washington in 2010, will focus on ways to safeguard atomic material worldwide and prevent acts of nuclear terrorism.

Kim said North Korea's nuclear programme would not be on the agenda but the summit may build momentum towards denuclearisation as it deals with highly enriched uranium and plutonium.

The North -- which last week agreed to a nuclear halt in exchange for food aid from the United States -- has blasted the summit as an "unsavoury burlesque" intended to justify an atomic attack.