U.S. passport holders will continue to be prohibited from traveling to North Korea after the U.S. State Department extended a travel ban on the country, according to a department spokesperson on Wednesday.

The ban was initially imposed in Sept. 2017 in response to the death of Otto Warmbier, an American student who was detained in North Korea and later returned to the U.S. in a comatose state, dying shortly after his release.

In an email to NK News, the spokesperson said the decision was made “due to continuing concerns over the serious risk of arrest and long-term detention in