"Today's actions are driven by our commitment to hold North Korea accountable for its destructive and destabilizing conduct. Even as the FBI continues its investigation into the cyber-attack against Sony Pictures Entertainment, these steps underscore that we will employ a broad set of tools to defend U.S. businesses and citizens, and to respond to attempts to undermine our values or threaten the national security of the United States," Treasury Secretary Jacob Lew said in a statement.
"The actions taken today under the authority of the President's new Executive Order will further isolate key North Korean entities and disrupt the activities of close to a dozen critical North Korean operatives. We will continue to use this broad and powerful tool to expose the activities of North Korean government officials and entities," he added. The individuals were not targeted because of any involvement in the Sony cyberattack, a senior U.S. official told Reuters.
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Experts had previously told CNBC that sanctions were likely to have little effect against North Korea—which is already under several international penalties.
"How do you sanction the world's most heavily sanctioned country?" John Park, a Northeast Asia specialist at Harvard Kennedy School, asserted in an interview last month. "Every time you apply sanctions to a target, it forces them to innovate and get around sanctions."
Other experts had suggested in December that the U.S. government might be able to hurt the regime by attacking its international exposure—either those foreign firms operating in North Korea, or North Korean entities operating abroad.
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This may account for the sanctioning of some of the officials with business ties to other countries, including Kil Jong Hun and Kim Kwang Yon, who the Treasury described as representing "the southern African interests" of the Korea Mining Development Trading Corp.
"The financial portion is what hurts them the most," Jack Pritchard, who served as U.S. ambassador and special envoy for negotiations with the Democratic People's Republic of Korea from 2001 to 2003, told CNBC last month. "I would not underestimate the value of financial sanctions.