The United States has extended its sanctions against North Korea for another year.

In a notice sent to Congress on Monday, U.S. President Barack Obama said North Korea poses an "unusual and extraordinary threat" to the U.S., and announced that his country will continue to extend the national emergency with respect to the threat from the communist state.

With this latest move, the U.S. economic sanctions on the North will remain valid until June of next year.

Former U.S. President George W. Bush signed an executive order in June 2008 dealing with the North's unusual and extraordinary threat to the U.S. national security.

The U.S. had removed North Korea from its list of terrorism sponsoring nations and stopped imposing sanctions on the communist state under the Trading with the Enemy Act after Pyongyang took some steps toward denuclearization, including declaring its nuclear program in June 2008. However, the U.S. had kept in place some sanctions, including the freezing of assets.