Matthew Miller, the Californian man detained in North Korea in April, has been sentenced to six years with labor on charges of trying to commit espionage, entering the country illegally according to the official North Korean news agency KCNA.

KCNA said that 24-year-old Miller committed hostile acts toward North Korea while under the guise of a tourist.

The Los Angeles Times reports that after Miller entered the country on April 10 and opted not to travel with staff from Uri Tours, the American company that booked the trip, or any other Western tourist but instead choose the more expensive option of traveling with North Korean Guides.

The USA Today reports that Miller tore up his visa while traveling and declared himself not a tourist. The prosecutor told the court Miller had a wild ambition of experiencing life as a prisoner in order to carry out a secret investigation on the human rights situation in North Korea.

Earlier this month, Miller told CNN that he "prepared to violate the law of DPRK before coming here. And I deliberately committed my crime." CNN reports that it is unclear whether or not the claims were made under coercion or at the free will of Miller.

The U.S. State Department has urged for his release.

Andrea Lee, chief executive at Uri Tours, said that new measures will be taken to more thoroughly screen passengers before their tours as a result of Miller's arrest and detention.

"Although we ask a series of tailored questions on our application form designed to get to know a traveler and his/her interests, it's not always possible for us to foresee how a tourist may behave during a DPRK (initals for the country's formal name, Democratic People's Republic of Korea.) tour," Lee said via email.