"U.S. economic sanctions imposed on North Korea are instigated by that country's activities related to weapons proliferation; regional disruptions; terrorism; narcotics trafficking; undemocratic governance; and illicit activities in international markets, including money laundering, counterfeiting of goods and currency, and bulk cash smuggling. […] Since the outbreak of the Korean War in 1950, the United States had imposed fairly comprehensive economic, diplomatic, and political restrictions on North Korea. In 1999, however, President Clinton announced he would lift many restrictions on U.S. exports to and imports from North Korea in areas other than those controlled for national security concerns; the Departments of Commerce, Treasury, and Transportation issued new regulations a year later that implemented the new policy. On June 26, 2008, President George W. Bush removed restrictions based on authorities in the Trading With the Enemy Act and the terrorism designation, replacing them with more circumscribed economic restrictions related to proliferation concerns."
CRS Report for Congress, R41438