Otto Frederick Warmbier, a University of Virginia student, entered the country on a tourist visa, according to Pyongyang's Korean Central News Agency.

The agency said his plan was to undermine the North's system (government) with the assistance of the U.S. government.

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Warmbier graduated in 2013 from Wyoming High School in Cincinnati. U.S. Rep. Brad Wenstrup, whose district includes the area where Warmbier attended high school, tweeted Friday his office was offering assistance in the investigation, CNN reported.

The arrest was announced early Friday morning.

The Associated Press contributed to this report.