U.S. President Barack Obama has signed an executive order imposing new sanctions on North Korea, in response to the authoritarian regime's latest nuclear and ballistic missile tests.
The executive order follows North Korea's nuclear test on January 6 and ballistic missile launch on February 7, in violation of long-standing international efforts aimed at curbing Pyongyang's nuclear ambitions.
White House press secretary Josh Earnest announced the president's decision Wednesday.
Earnest said the new unilateral sanctions will allow the U.S. to implement sanctions unanimously agreed to by the U.N. Security Council.
"The U.S. and the global community will not tolerate North Korea's illicit nuclear and ballistic missile activities, and we will continue to impose costs on North Korea until it comes into compliance with its international obligations," he said.
The sanctions are designed to freeze the assets of anyone who breaks the international blockade on North Korea, meaning even the few nations that do engage in trade with North Korea, such as China, will be discouraged from doing so.
The order also targets North Korea's human rights abuses, allowing the U.S. Treasury Department to freeze assets of any party found to have engaged in exportation of workers from North Korea. A U.N. report found last year that Pyongyang earns as much a $2.3 billion a year from workers exported to other countries, where they are often abused and exploited.
The report said about 50,000 North Koreans are believed to be working overseas, earning small amounts for themselves while the employers pay a much greater amount to the North Korean government. Workers are forced to labor as long as 20 hours a day, with very few days off, according to the report.
Also Wednesday, the White House appealed to North Korea to pardon an American college student sentenced to 15 years of hard labor for committing crimes against the state.
White House spokesman Josh Earnest said Wednesday that it is "increasingly clear" that Pyongyang is using U.S. citizens as "pawns to pursue a political agenda."
North Korean police arrested 21-year-old Otto Warmbier as he was trying to leave the country after visiting with a tour group in January.
Warmbier, a student at the University of Virginia, appeared at a news conference in Pyongyang and admitted stealing a banner with a political slogan from an area of his hotel that was off-limits to guests.
Warmbier said a friend's mother offered him a used car worth $10,000 in exchange for the banner. He said she wanted to hang it in her church as a trophy. She allegedly offered Warmbier's mother $200,000 if he was caught.
As in all cases involving Westerners jailed in North Korea, Warmbier's confession likely was coerced and the alleged crimes exaggerated.
Just hours before Warmbier was sentenced, former U.S. ambassador Bill Richardson said he met with two North Korean diplomats at the United Nations in New York and appealed for the student's release.
Richardson has gone to North Korea several times in recent years to secure freedom for jailed Americans.