At least 14 U.S. citizens have been detained in the DPRK in the past ten years.  North Korea has detained those who traveled independently and those who were part of organized tours.  Being a member of a group tour or using a tour guide will not prevent North Korean authorities from detaining or arresting you.  Efforts by private tour operators to prevent or resolve past detentions of U.S. citizens in the DPRK have not been successful.

If you decide to enter North Korea against the advice of this Travel Warning, you should have no expectation of privacy.  All electronic and multimedia devices including USB drives, CDs, DVDs, mobile phones, tablets, laptops, Internet browsing histories and cookies are subject to search for banned content.

If DPRK authorities permit you to keep your mobile phone when you enter the country, it will not function unless you use the DPRK mobile service, which will enable DPRK authorities to monitor your calls.  GPS-trackers and satellite phones are not allowed. 

Possession of any media, either physical or electronic, criticizing the DPRK government or its leaders is considered a criminal act punishable by long-term detention in hard labor camps and heavy fines. 

In North Korea, the following – whether done knowingly or unknowingly – have been treated as crimes:

• Showing disrespect to the country’s former leaders, Kim Il Sung or Kim Jong Il, or for the country’s current leader, Kim Jong Un, including but not limited to tampering with or mishandling materials bearing their names or images;
• Entering North Korea without proper travel documentation;
• Possessing material that is in any way critical of the DPRK government;
• Proselytizing or carrying out religious activities, including activities that may be construed as such, like leaving behind religious materials;
• Engaging in unsanctioned political activities;
• Traveling without authorization, even for short distances;     
• Having unauthorized interaction with the local population;
• Exchanging currency with an unauthorized vendor;
• Taking unauthorized photographs;
• Bringing pornography into the country;
• Shopping at stores not designated for foreigners; and
• Removing or tampering with political slogans and signs or pictures of political leaders.

...

The United States and the United Nations Security Council have expressed grave concern regarding North Korea’s recent nuclear tests, ballistic missile launches, and other activities prohibited by United Nations Security Council Resolutions.  UN Security Council statements from January 2016 and March 2016 are posted on the UN website. 

As a result of concerns arising from unannounced missile launch activities and GPS navigation systems interference and/or disruption, the Federal Aviation Administration (FAA) has issued a Prohibition and Advisory notice to U.S. airmen and operators.  The FAA has issued Special Federal Aviation Regulation (SFAR) 79 which prohibits U.S. civil aviation from flying in the Pyongyang Flight Information Region (FIR) (ZKKP) west of 132 degrees east longitude, and the FAA has advised those flying in and around the Pyongyang FIR (ZKKP) east of 132 degrees east longitude to be aware of possible GPS interruptions.  For more information, U.S. citizens should consult the Federal Aviation Administration’s Prohibitions, Restrictions and Notices.

For further information:

• See the State Department's travel website at travel.state.gov for current Worldwide Cautions, Travel Warnings, Travel Alerts, and Country Specific Information for North Korea.
• Enroll in the Smart Traveler Enrollment Program (STEP) to receive important safety and security messages via email (though you may not have access to email while in North Korea).  Enrollment also makes it easier to locate you in case of an emergency.
• U.S. citizens who plan to travel to North Korea are strongly encouraged to inform the U.S. Embassy in Beijing, China by enrolling in STEP.  U.S. citizens residing in China can contact the U.S. Embassy directly.  The Embassy is located next to the Ladies’ Street (Nuren Jie) and Laitai Flower Market, near the Kempinski Hotel and Lufthansa Shopping Center on Tianze Road near the Liangmaqiao subway stop:

           U.S. Embassy in Beijing
           American Citizens Services Unit
           No. 55 An Jia Lou Road
           Chaoyang District
           Beijing, China 100600
           Telephone:  (86-10) 8531-4000
           Email:  BeijingACS@state.gov 
           Emergency after-hours number for U.S. citizens:  (86-10) 8531-4000

• U.S. citizens traveling to North Korea are also strongly encouraged to contact the Embassy of Sweden by telephone or email prior to travel.  Please provide the Embassy of Sweden with your name, date of birth, dates of your trip, and emergency contact information: 

           The Embassy of Sweden Pyongyang (U.S. Protecting Power in North                Korea)
           Munsu-Dong District
           Pyongyang, DPRK
           Telephone:  (850-2) 3817 485 (reception)
           Telephone:  (850-2) 3817 904, (850-2) 3817 907 (Deputy)
           Telephone:  (850-2) 3817 908, (850-2) 3817 905 (Amb.)
           Facsimile:  (850-2) 3817 663
           Email:  ambassaden.pyongyang@gov.se

If you provide information to the U.S. Embassy in Beijing or the Swedish             Embassy in Pyongyang, officials will be able to locate you more easily in             an emergency.  Take note of and keep the contact details for the Swedish           embassy for easy access in case of an emergency.

• U.S. citizens can obtain current information on safety and security conditions by calling 1-888-407-4747 toll-free in the United States and Canada or 1-202-501-4444 from other countries from 8:00 a.m. to 8:00 p.m. Eastern Standard Time, Monday through Friday (except U.S. federal holidays).

Full Warning: https://travel.state.gov/content/passports/en/alertswarnings/north-korea-travel-warning.html