North Korea delivered its most in-depth account yet of the case against a Korean-American sentenced to 15 years' hard labor, accusing him late Thursday of smuggling in inflammatory literature and trying to establish a base for anti-Pyongyang activities at a border city hotel.

Still, the long list of allegations included no statement from Kenneth Bae, other than claims that he confessed and didn't want an attorney present during his sentencing last week for what Pyongyang called hostile acts against the state.

Since the sentencing came during a period of tentative diplomatic moves following weeks of high tension and North Korean threats of nuclear and missile strikes on Washington and Seoul, outside analysts have said Pyongyang may be using Bae as bait to win diplomatic concessions in the standoff over its nuclear weapons program. North Korea repeated its denial of such speculation in the new statement, but the pattern has occurred repeatedly.

The North's state media described the statement from an unidentified Supreme Court spokesman as a response to U.S. government and media assertions that the legal case against Bae was unreasonable and other claims ``that he was not tried in a transparent manner and (the North) was trying to use this issue as a political bargaining chip.'' The spokesman said Bae, 44, could've faced death but the court reduced the penalty because he confessed. He was arrested in North Korea in November.

Bae, a Washington state resident described by friends as a devout Christian and a tour operator, is at least the sixth American detained in North Korea since 2009. The others eventually were deported or released without serving out their terms, some after trips to Pyongyang by prominent Americans, including former presidents Bill Clinton and Jimmy Carter. There has been no sign yet of a high-profile American envoy set to make a clemency mission to North Korea, which has only recently eased a near-daily, weekslong torrent of threats that followed greater U.N. sanctions over Pyongyang's February nuclear test.

The North's statement said Bae gave anti-Pyongyang lectures in China and ``infiltrated'' about 250 students into the city of Rason, a special economic zone in North Korea's far northeastern region bordering China and Russia. It didn't elaborate on the students' activities, however.

Young leader Kim Jong Un has the power to grant special pardons under the North's constitution. Earlier this week, former NBA star Dennis Rodman attempted to use his friendship with Kim on Bae's behalf, asking the leader to ``do me a solid'' and release the American. Rodman visited North Korea in February and apparently hit it off with Kim, a die-hard basketball fan. Pyongyang hasn't responded to Rodman's appeal on Twitter. Rodman said after his trip to North Korea that he planned to return in August to vacation with Kim.

The U.S. has called for the North to immediately release Bae. It relies on Swedish diplomats in Pyongyang to deal with Bae's case because the North and the U.S. have had no formal diplomatic relations since the 1950-53 Korean War ended in a truce instead of a peace treaty.

North Korea said in the statement that Bae ``set up plot-breeding bases in different places of China for the purpose of toppling (North Korea's) government from 2006 to October 2012 out of distrust and enmity toward the'' country. ``He committed such hostile acts as egging citizens of (North Korea) overseas and foreigners on to perpetrate hostile acts to bring down its government while conducting a malignant smear campaign against it. He was caught red handed.''

North Korea refers to Bae as Pae Jun Ho, the North Korean spelling for his Korean name.

North Korea has faced increasing international criticism over its weapons development. Six-nation disarmament talks involving the Koreas, the United States, Japan, China and Russia fell apart in 2009. Several rounds of U.N. sanctions have not encouraged the North to give up its small cache of nuclear devices, which Pyongyang says it must not only keep but expand to protect itself from a hostile Washington. Tensions have escalated since it conducted its third nuclear test since 2006 in February.

The human rights group Amnesty International has criticized Bae's lack of access to a lawyer and called for his release.

Friends and colleagues say Bae was based in the Chinese border city of Dalian and traveled frequently to North Korea to feed orphans. (AP)