The South Korean Foreign Ministry announced on Tuesday that it would join the Proliferation Security Initiative, which began in 2003 to deter states such as North Korea and Iran from trade in missile and nuclear technology.

North Korea has warned it would consider the South's full participation in the programme as a declaration of war.

South Korea had planned to join the programme following the North's April 9 rocket launch, but delayed the announcement after a surprise offer of a dialogue by the North. -- AP

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