U.S. citizens who visit North Korea face a high risk of wrongful detention by the government, the State Department said this week, slapping a new travel warning on the DPRK and five other countries.

Secretary of State Antony Blinken introduced the new “D” indicator to official travel advisories on Tuesday, saying that the mark would highlight dangers of going to countries that may target individuals “because of their U.S. citizenship or ties to the United States or use them as a bargaining chip.”