The United States has imposed sanctions on three North Korean entities and one trading firm official for their involvement in the proliferation of weapons of mass destruction, the State Department said Monday.



The North's General Department of Military Cooperation, the Namhung Trading Corp. and Saeng Pil Trading Corp. were slapped with sanctions under the Iran, North Korea and Syria Nonproliferation Act, according to a State Department notice to the Federal Register.



Kang Mun-kil, believed to be the head of the Namhung Trading Corp., was also on the sanctions list.



The notice, dated July 5, did not provide further details, including what the North Korean entities and individual specifically did. But they have long been accused of involvement in WMD proliferation and have already been on the list of other sanctions.



They were among a total of 36 entities and individuals that the department hit with sanctions under the nonproliferation act. The others included firms and individuals from China, Russia, Iraq, Iran, Malaysia, Sudan and Uganda.



Under the measure, U.S. government agencies are banned from dealing with the sanctioned entities. However, sanctions on the North Korean entities and individual will largely be symbolic because they are not believed to have any dealings with U.S. government agencies.



The U.S. has been trying to increase pressure on Pyongyang after the North's fourth nuclear test and a long-range rocket launch the following month.



The U.S. has led the U.N. Security Council to adopt the toughest sanctions ever on Pyongyang while enacting its own unilateral sanctions on the communist nation.



Last month, the Treasury Department also designated the North as a "primary money laundering concern," a powerful sanction designed to cut off the provocative regime from the international banking system for defiantly pursuing nuclear and missile development.



Sources have said that the U.S is putting together new sanctions on the North over its human rights abuses.



The North Korea Sanctions and Policy Enhancement Act, enacted in February, calls for the government to submit a specific report on Pyongyang's human rights abuses within 120 days.



Under the law, the State Department could soon announce sanctions blacklisting about 10 North Korean officials for human rights violations, the sources said. (Yonhap)