The Trump administration is expected to ban U.S. citizens from traveling to North Korea, according to a report Friday morning.

State Secretary Rex Tillerson will impose a "geographic travel restriction" for North Korea. The ban would make it illegal to use a U.S. passport to enter Kim Jong Un's country.

The change will go into effect 30 days after Tillerson's notice is published in the Federal Register, the Associated Press reported.

Two tour companies told the AP they were informed of the change before Friday. One such company, Beijing-based Koryo Group, expects the new policy to affect 800 to 1,000 Americans to visit North Korea each year.

This type of travel ban was first used in 1967 and has since been carried out against Algeria, Iraq, Lebanon, Sudan, Cuba and North Vietnam.

North Korea currently has three American citizens in detention. In June, North Korea released 22-year-old Otto Warmbier, who had been imprisoned for allegedly stealing a propaganda poster while visiting the country. Warmbier returned to the U.S., but died days after making it back to his family due to injuries he likely sustained while in North Korean custody.