North Korea held the trial of American citizen, Matthew Miller, detained in April for violating his tourist status in the country, the Associated Press reported on Sunday. The first hearing was held on Sunday morning, but details concerning specific charges against Miller or potential punishment have not yet been disclosed. In April, US citizen Matthew Miller from Bakersfield, California, was detained by North Korean authorities for allegedly tearing up his visa upon entering the country at Pyongyang's airport and demanding asylum, according to the Associated Press. Miller was arrested at passport control on April 10. Another American tourist awaiting trial, Jeffrey Fowle, was arrested in May for leaving a Bible at a provincial club while Korean-American missionary Kenneth Bae is currently serving out a 15-year sentence for alleged "hostile acts." All three Americans participated in an exclusive CNN interview earlier this month where they admitted to committing acts against North Korea and publicly apologized, but it is unclear whether confessions were made freely or under coercion by North Korean authorities. Miller and the other two detained, called on Washington to secure their release. The United State has responded by repeatedly offering to send its envoy for North Korean human rights issues, Robert King, to seek pardon for the US citizens to no avail. Miller traveled to North Korea after arranging a private tour through Uri Tours which takes tourists into North Korea, despite US State Department warnings to American citizens of arbitrary arrest and detention in the country, CNN reported.