The measures, if enacted, are expected to further squeeze North Korea's foreign currency earnings, which are believed to be funneled into its development of nuclear weapons and missiles.

After a trilateral meeting of the three countries' envoys on the North Korean nuclear issue in Tokyo on Tuesday, South Korea's Kim Hong-kyun said they agreed to take "unbearably strong punitive action" if the North goes ahead with a strategic military provocation amid signs that the North is preparing its sixth nuclear test or the first ICBM launch.

The trade of fishing rights with China and the dispatch of workers overseas are key foreign currency income sources for North Korea.

North Korea is believed to have sold to China the rights to fish in the waters along the Northern Limit Line, the de facto maritime demarcation between the two Koreas. North Korea reportedly earned $75 million from the transaction with China.

Whether it would be possible remains to be seen, as adding the new measure to a UNSC resolution requires consent from China, the biggest ally of North Korea, as well as the dominant buyer of North Korean fishing rights and a permanent member of the UNSC. (Yonhap)