03/27/2012 07:33 EDT | Updated 05/27/2012 05:12 EDT

World leaders vow nuclear security action

Leaders from more than 50 countries have wrapped up a conference on nuclear security in Seoul, South Korea, by pledging to work together to tackle the threat of nuclear terrorism.

They agreed to work on securing all nuclear material by 2014.

"The security of the world depends on the actions that we take," U.S. President Barack Obama said Tuesday at the end of the two-day meeting.

"There are still too many bad actors in search of these dangerous materials and these dangerous materials are still vulnerable in too many places. It would not take much — just a handful or so of these materials — to kill hundreds of thousands of innocent people."

Britain's deputy prime minister, Nicholas Clegg, said his country would share with other countries some previously secret ways of detecting radiological material. "We have for some time had specialist teams ready to deploy, detect and ... defuse a terrorist nuclear device," Clegg revealed.

Clegg told the summit he was publicizing the secret work because Britain was planning to open a new nuclear forensics lab that would share detection techniques with allies.

North Korean rocket

The meetings took place against the backdrop of North Korea's threat to test-fire a long-range rocket in April.

Prime Minister Stephen Harper said that while North Korea was not on the official agenda, it was the subject of much discussion.

He was due to arrive back in Canada by 9 p.m. ET.

Harper said Canada can only join the rest of the world in trying to persuade North Korea to cancel its missile test, although he's not sure how much good that will do.

"Unfortunately, this regime seems to delight in irritating the international community," Harper said.

Nuclear safety was not the only thing on Harper's mind, as trade was the focus of his bilateral meetings on the summit's sidelines.

Fresh off trade visits to Japan and Thailand, Harper couldn't help but discuss business. In meetings with the European Union, India and Italy, Harper brought up trade and made no apologies for it.

"I don't think it's any secret, if you talk to most leaders today, the economic circumstances of the global economy and their own economies are very much centre and very much top of mind," Harper said.

"We're working hard here to work with others and increase jobs, growth and long-term prosperity. Ultimately, our view as a trading nation, in a global economy, [is] all of our interests are linked."

The prime minister is en route back to Canada and expected to arrive in Ottawa Tuesday evening.