North Korea has revised its criminal law in a bid to safeguard its communist regime and boost its impoverished economy.

Diplomatic sources in Pyongyang said the revision, the fifth since 1950, can be viewed as Pyongyang's efforts to support its macroeconomic reforms and attract foreign investors.

The revision also calls for strengthened legal measures to protect private property, intellectual rights, copyrights and trademark rights.

The revised code has also cut the jail term from three to two years for those caught leaving the country for non-political reasons, such as earning money in China. The North is openly calling on those "economic migrants" to return to their communist homeland, promising to pardon them.