N. Korea sentences U.S. citizen to 15 years of labor

North Korea's Supreme Court has sentenced a Korean-American man to 15 years of compulsory labor for "committing hostile acts" against the country, its official Korean Central News Agency reported Thursday.

Meanwhile, South Korea's Yonhap News Agency reported that former U.S. President Jimmy Carter may soon travel to North Korea to work for the release of the man, who has been detained there for nearly half a year, and to broker resumption of dialogue between Pyongyang and Washington.

KCNA, monitored in Beijing, said the sentence was handed down to Pae Jun Ho, known in the United States as Kenneth Bae, at his trial on Tuesday.

The report said he "was arrested while committing hostile acts against the DPRK after entering Rason City as a tourist on Nov. 3 last year." It did not specify what he did that was illegal.

DPRK is an acronym for North Korea's official name, the Democratic People's Republic of Korea. Rason is a special economic zone near the border with China.

On Monday, the U.S. State Department called on North Korea "to release Kenneth Bae immediately on humanitarian grounds."

The department said it has been closely coordinating with the Swedish Embassy in the North Korean capital, which helps out with issues involving U.S. citizens in North Korea in the absence of diplomatic relations between Washington and Pyongyang. Swedish Embassy personnel visited him on April 26, it said.

According to U.S. media reports, Bae is believed to be a tour operator in his mid-40s who hails from Washington state.

There has been speculation that North Korean authorities were angered by photographs Bae had reportedly taken of malnourished children and the public executions of dissenters.

Bae is the sixth U.S. citizen to be detained by North Korea since 2009. The other five were freed through contacts with the United States.

Yonhap, in a report from Washington, cited a diplomatic source as saying Carter recently sent a letter to Secretary of State John Kerry in which he said he intends to visit North Korea again as a private citizen.

"North Korea appears to have invited him to visit," the source was quoted as saying.

Carter, who served as U.S. president from 1977 to 1981, has previously visited North Korea as a member of The Elders, an independent group of about 10 former heads of state.

In 2010, he negotiated the release of American national Aijalon Mahli Gomes, who had been sentenced to eight years of hard labor after illegally crossing into North Korea from China. The ex-president's most recently visit was in April 2011.

During a trip to Pyongyang in early January, a U.S. private delegation including former New Mexico Gov. Bill Richardson and Google Inc. Executive Chairman Eric Schmidt asked North Korean officials to extend humanitarian treatment to Bae, but it was unable to meet him, much less secure his release.