World leaders have called for closer co-operation to tackle the threat of nuclear terrorism at a summit on nuclear security in Seoul.
A communique at the end of the Second Nuclear Security Summit reiterated a joint call to secure "vulnerable nuclear material", the BBC reports.
South Korean President Lee Myung-bak says nuclear terrorism remains a "grave threat", while US President Barack Obama says action is key.
The meeting was dominated by North Korea's plan to launch a satellite into orbit next month, which the US says is a pretext for a ballistic missile test.
At the summit Mr Obama urged his Chinese counterpart Hu Jintao to do more to restrain North Korea. The two leaders agreed to work together to stop North Korea's launch.
The BBC reports 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.
Meanwhile, a private conversation between President Obama and Russian President Dmitry Medvedev at the summit has been picked up by microphones.
The US leader told Mr Medvedev he would have have more flexibility to negotiate on America's planned missile defence system in Europe after this November's presidential election.
The Third Nuclear Security Summit will be held in the Netherlands in 2014.
Important step - NZ PM
New Zealand Prime Minister John Key, who was one of the leaders of the 53 states represented at the summit, described it as another important step towards securing nuclear materials and reducing the global threat of nuclear terrorism.
Mr Key also announced New Zealand will contribute $500,000 towards a US-led project to remove highly-enriched uranium from Uzbekistan back to Russia to be reprocessed and securely stored.
"This project reinforces our support for the securing of vulnerable nuclear materials worldwide."
Mr Key says New Zealand has a strong and principled voice on nuclear issues so it has an important role to play in the process.
"My statement to the summit ... reinforced that, even as a small country, we are not immune to the risks posed by nuclear terrorism.
"I urged my counterparts to take seriously the commitments we made at the last Summit in Washington in 2010 and to push further to ensure nuclear materials don't fall into the wrong hands."
Mr Key also held bilateral meetings with several leaders on the last day of the summit including Vietnam Prime Minister Nguyen Tan Dung, Thailand Prime Minister Yingluck Shinawatra, Chilean President Sebastian Pinera, and Canadian Prime Minister Stephen Harper.