North Korea says that it has sentenced detained U.S. citizen Kenneth Bae to 15 years of hard labor for crimes of hostile activities and attempting to overthrow the North.

North Korea’s state-run Korean Central News Agency said Thursday that North Korea’s Supreme Court handed down the verdict after trying Bae on Tuesday.

North Korean authorities said that Bae admitted to charges against him in a recently completed preliminary inquiry. However, Pyongyang did not elaborate on the details of charges against him.

Bae operates a travel agency in China and was arrested in November last year while accompanying five European tourists into North Korea’s Rason Special Economic Zone.

North Korea has a history of detaining U.S. citizens and putting them on trial as a way to draw high-ranking U.S. officials to the North for negotiations.