In a move which has been widely anticipated, the U.S. State Department announced Wednesday that U.S. citizens will no longer be able to travel to North Korea starting September 1st. Those currently in North Korea on U.S. passports have been advised to leave the country in the next 30 days.

The State Department said that the travel ban is in response to “the serious risk to United States nationals of arrest and long-term detention.” The decision seems to be a direct response to the death of 22-year-old American traveler Otto Warmbier, who was arrested while vacationing in North Korea and then sentenced to 15 years of hard labor after being convicted of trying to steal a poster from his hotel. Warmbier was held in North Korea for nearly a year and a half, and when he was released and returned to the United States in June of this year, he was in a coma and died six days later. A physician who examined his brain said that he had suffered “extensive loss of tissue.”

North Korea will join Cuba as the second country to which the U.S. government has banned travel. Though the Obama administration rolled back long-standing barriers preventing travel to Cuba, Trump more recently indicated his desire to reinstate tighter controls over citizens traveling between the two nations.