( CNN ) -- North Korea said Wednesday that the U.S. citizen it sentenced last month to 15 years of hard labor has begun his stay at a `` special prison . '' Kenneth Bae , who the North Koreans refer to as Pae Jun Ho , was arrested in November in Rason city , a port in the northeastern corner of North Korea . Opinion : When Americans are held in global power games . North Korea accuses him of seeking to bring down the regime of Kim Jong Un , but the United States and his family say he was just working as a tour operator . In a short article Wednesday , the North 's state-run Korean Central News Agency ( KCNA ) said Bae had `` started his life at a 'special prison ' on Tuesday . '' It did n't give any details about the prison . The United States has repeatedly called on North Korea to grant Bae amnesty and release him immediately , but the requests so far do n't appear to have gained any traction following a period of heightened tensions between the two countries . Even a plea last week for Bae 's release from the basketball star Dennis Rodman , who met with Kim Jong Un during a bizarre visit to North Korea in February , has failed to have any apparent effect . North Korea outlines accusations against Bae . Accused of 'hostile acts ' Last week , KCNA cited a spokesman for the North Korean Supreme Court as saying that Bae , a Korean-American tour operator , set up anti-North Korean bases in China and distributed anti-regime literature . `` He committed such hostile acts as egging citizens of the DPRK overseas and foreigners on to perpetrate hostile acts to bring down its government while conducting a malignant smear campaign against it , '' the court said , using the shortened version of the country 's official name , the Democratic People 's Republic of Korea . He was accused of preaching at churches and lecturing to groups about the need to escalate confrontation , the court said . NK News , a U.S.-based website that focuses on North Korea , has suggested Bae has served as a missionary trying to convert North Koreans . Opinion : What North Korea could learn from Myanmar . `` I knew that Jesus wanted me to be a 'channel ' to the North , '' Bae told a Korean congregation at a St. Louis church in 2011 , NK News reported last week . `` This year , I 'm working at taking several short term missionary teams into North Korea . '' Bae 's sister , Terri Chung , said earlier this month that her brother `` never had any evil intentions against North Korea . '' She said Bae was in the country for work related to the tour company he owns . He had traveled to the country previously with no problems and had no reason to suspect that this time would be different , Chung told CNN 's Anderson Cooper . Not a 'bargaining chip ' In the past , North Korea has released Americans in its custody after visits by a U.S. dignitary -- in recent examples , former Presidents Jimmy Carter and Bill Clinton . But North Korea said earlier this month that Bae is not a `` political bargaining chip . '' His case `` proves that as long as the U.S. hostile policy toward the DPRK remains unchanged , humanitarian generosity will be of no use in ending Americans ' illegal acts . '' Read more : How a voice from a North Korean gulag affected human rights discourse . Tensions between Pyongyang and Washington spiked in March and April amid a flurry of fiery North Korean threats against the United States and South Korea . The angry rhetoric appeared to be fueled by tougher U.N. sanctions against the North after its underground nuclear test in February , as well as by annual military drills in the region by the United States and South Korea . The intensity of the North 's rhetoric appears to have subsided in recent weeks , and the U.S.-South Korean drills finished at the end of April . North Korea is considered to have one of the most repressive penal systems in the world . Human rights groups estimate that as many as 200,000 people are being held in a network of prison camps that the regime is believed to use to crush political dissent .
A court sentenced Kenneth Bae to 15 years of hard labor last month . North Korea accuses him of trying to bring down the state . State media say he has now `` started his life at a 'special prison ' '' The United States has repeatedly called for Bae 's immediate release .