It will no longer be legal to use a U.S. passport to enter North Korea as of September 1, the State Dept. announced on Wednesday. This travel restriction will stay in place for a year, unless Secretary of State Rex Tillerson chooses to extend or revoke the policy. This policy means that a U.S. passport cannot be used to travel "to, in, or through the DPRK" without a special permission to do so. Americans who are currently in North Korea are told that they should leave the country.
The full text of the announcement explains that the State Department no longer thinks it is safe for Americans to enter North Korea due to the risk of "arrest and long-term detention."
United States Passports Invalid for Travel to, in, or Through the Democratic People’s Republic of Korea
The Department of State has determined that the serious risk to United States nationals of arrest and long-term detention represents imminent danger to the physical safety of United States nationals traveling to and within the Democratic People’s Republic of Korea (DPRK), within the meaning of 22 CFR51.63(a)(3). Therefore, pursuant to the authority of 22 U.S.C. 211a and Executive Order 11295 (31 FR 10603),and in accordance with 22 CFR51.63(a)(3), all United States passports are declared invalid for travel to, in, or through the DPRK unless specially validated for such travel, as specified at 22 CFR 51.64. The restriction on travel to the DPRK shall be effective 30 days after publication of this Notice, and shall remain in effect for one year unless extended or sooner revoked by the Secretary of State.
Back in July, officials said that some sort of travel ban was in the works, but it was not announced until yesterday.
This new policy was stems from the recent death of Otto Warmbier, an American college student who was imprisoned in North Korea after being accused of stealing a propaganda poster from his hotel. In a show trial, Warmbier gave an obviously-coerced "confession" and was sentenced to 15 years of hard labor. Shortly afterwards, Warmbier fell into a coma, and he passed away a few days after he was transported back to the United States.
Given that relatively few westerners, never mind Americans, travel to North Korea each year, this policy shouldn't mess up too many travel plans.