SEOUL (AFP) - A Korean-American detained in North Korea admitted to attempting to steal military secrets as he was paraded in front of media groups in Pyongyang on Friday (March 25).

Kim Dong Chul, 62, who became a naturalised US citizen in 1987 and was arrested on espionage charges in October last year, pleaded for mercy during his carefully orchestrated confession, Japan's Kyodo news agency reported.

His detention first came to public attention when he was produced in January during an interview CNN was conducting with a detained Canadian pastor in a Pyongyang hotel.

At that time, Kim said he had been living in China near the North Korean border for the past 15 years, commuting regularly to Rason - a North Korean special economic zone.

Kim was arrested in October last year in Rason as he was receiving USB stick containing nuclear-linked and military secrets from his source, Pyongyang's official KCNA news agency said on Friday.

Kim admitted to having been in contact with South Korean intelligence since 2011, who had funded his espionage activities, KCNA said.

The US citizen said he had collected intelligence on the party, the state and the military and handed them over to South Korean spies, according to KCNA.

Foreigners detained in North Korea are often required to make a public, usually officially-scripted acknowledgement of wrongdoing as a first step towards a possible release.

Kim's appearance came a week after a North Korean court sentenced an American student who admitted stealing a propaganda banner from a hotel to 15 years' hard labour.

Observers said the harsh sentence reflected soaring military tensions on the divided Korean peninsula following the North's nuclear test in January and long-range rocket launch a month later.

The United States took a leading role in securing the resulting sanctions that the UN Security Council imposed on the North earlier this month.