World leaders: Nuclear terrorism a 'grave threat'

World leaders have called for closer co-operation to tackle the threat of nuclear terrorism at a summit on nuclear security in Seoul.

South Korean President Lee Myung-bak said nuclear terrorism remained a "grave threat", while US President Barack Obama said action was key.
Chinese President Hu Jintao urged the group to work together on the issue.
Chinese President Hu Jintao urged the group to work together on the issue.
The meeting has so far been dominated by North Korea's plan to launch a rocket next month.
North Korea says the long-range rocket will carry a satellite. The US says any launch would violate UN resolutions and constitute a missile test.
Iran's nuclear programme was also on the minds of the summit participants, with Mr Obama pledging to meet the leaders of Russia and China on the sidelines to work towards a resolution
At the meeting, world leaders are discussing measures to fight the threat of nuclear terrorism, including the protection of nuclear materials and facilities, as well as the prevention of trafficking of nuclear materials

There are currently no binding international agreements on how to protect nuclear material stored peacefully inside its home country, says the BBC's correspondent in Seoul, Lucy Williamson. An amendment seeking to do that is still unratified after seven years.

Addressing the summit, Mr Obama warned there were still "too many bad actors'' who were threatening to stockpile and use ''dangerous'' nuclear material.
"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," he said.

Rocket launch
Meetings on Monday were overshadowed by North Korea's planned launch, scheduled to take place between 12 and 16 April.
Pyongyang says it is intended to mark the 100th anniversary of the birth of North Korea's founding leader Kim Il-sung.On Tuesday, a North Korean foreign ministry spokesman said that the launch will go ahead as planned and criticised Mr Obama's stance as ''confrontational''.
North Korea ''will never give up the launch of a satellite for peaceful purposes''', the spokesman said in a statement in the official KCNA news agency.
"The security of the world depends on the actions that we take."
"The security of the world depends on the actions that we take."
Mr Hu called for "an international environment conducive to boosting nuclear security" to be created and Mr Lee called for concrete action to tackle a threat that posed "a grave challenge" to peace.
The summit, attending by almost 60 leaders from around the world, is due to issue a communique later in the day.