By Chris Buckley and Jeremy Laurence
SEOUL/BEIJING (Reuters) - The heir-apparent to North Korean leader Kim Jong-il arrived in China on Friday, possibly with his uncle and political minder, South Korean media reported, in his first official trip outside the isolated state.
Kim Jong-un had arrived by train in Tumen, in the northeastern Chinese province of Jilin, Yonhap news agency quoted a source in Tumen as saying. It quoted a government official in Seoul as saying he was unlikely to go to Beijing.
Reclusive North Korea is preparing for a third generation of Kim family rule, with the young and inexperienced Kim poised to take over from his father as the autocratic state's next leader.
Analysts say the succession process, hastened last September due to Kim Jong-il's poor health, has probably slowed down in recent months due to the 69-year-old leader's apparent improving condition.
South Korea's spy agency has been expecting the visit for months. Media reports said the trip was most likely designed to further economic ties between the neighbors and could involve visits to joint projects on their border.
The Chosun Ilbo website reported that Kim and his uncle Jang Song-thaek, the vice chairman of the National Defense Commission, could stay on to attend a groundbreaking ceremony for two development projects on the North Korea-China border at the end of the month.
A construction project of developing an island called Hwanggumpyong in the lower reaches of the Tumen River starts on May 28, and construction of roads connecting Hunchun in China and Rajin-Sonbong in North Korea on May 30, the paper said.
South Korean government officials could not immediately confirm the visit. "We are closely monitoring developments in the situation," a foreign ministry official said.
North Korea has dramatically increased its economic cooperation with China over the past two years to circumvent a raft of international sanctions imposed for its nuclear and missile tests in 2009.
South Korea and the United States have subsequently tightened sanctions following two attacks on the peninsula last year which killed 50 South Koreans.
Trade with China rose from US$2.68 billion in 2009 to $3.47 billion last year, media reports say.
Zhang Liangui, an expert on North Korea at the Central Party School in Beijing which trains Chinese officials, said that if confirmed, Kim's trip was meant extract more aid and support from China.
But Zhang said Kim Jong-un would not be the one to hammer out specifics of any new agreements with China. "Kim Jong-un wouldn't understand that kind of thing. He wouldn't have deciding authority over that either."
DIPLOMACY IN ACTION
The 27 or 28-year-old Kim is taking the next big step to succeeding leader Kim Jong-il by visiting China, introducing himself to the destitute North's main benefactor.
The youngest of the leader's three sons, little is known about Kim, not even his age. He was most likely born in 1984.
Educated in Switzerland, he is thought to speak English and German, and bears a striking resemblance to his grandfather, the North's founder Kim Il-sung.
Analysts say two attacks on the peninsula last year were aimed at winning the army's support for a continuation of dynastic rule and underscored an intent to maintain the state's military-first policy.
Experts say the young Kim will likely follow the same militaristic path, maintaining a strong grip over one of the world's largest armies and pressing on with a nuclear weapons programme in the face of international outrage.
Kim Jong-il last year promoted Jang, his brother-in-law, to the powerful National Defense Commission, which many analysts took to be an attempt to establish a mechanism for the eventual transfer of power, with Jang as regent while his nephew establishes himself in power.
(Additional reporting by Seoul Newsroom; Editing by David Chance and Jonathan Thatcher)