South Korean government sources say Kim Jong Un apparently crossed into China on Friday at the border city of Tumen. The visit is seen as making crucial personal connections in the country that is North Korea?s most important friend.
Media reports in Seoul say the North Korean heir-apparent then visited Mundanjiang, a tourist destination. He is also expected to stop in Harbin and Changchun in northeastern China. North Korean leader Kim Jong Il visited the same cities last August.
Yang Moo-jin, a professor at the University of North Korean Studies in Seoul, says the route suggests Kim's visit may not last more than a couple of days.
Professor Yang says if Beijing is on the agenda then the trip might extend to four or five days. He says that cannot be ruled out, but would likely have to include a meeting with Chinese President Hu Jintao to send the right signals to the international community.
Yang says China is an obvious choice for Kim Jong Un?s first official overseas trip. He explains that Kim is highly likely to be promised China?s firm support and cooperation on the succession plan. And there will be discussions about Chinese economic support, as well.
China, in addition to being North Korea?s most significant diplomatic ally, is the impoverished country?s primary source of food and other aid.
A spokesman for South Korea?s Unification Ministry, Chun Hae-sung, says the visit, if confirmed, is no surprise as Seoul has been anticipating that the younger Kim would make such a trip.
Chun says the South Korean government is closely monitoring the situation, but since neither Beijing nor Pyongyang has publicly confirmed the visit the Unification Ministry cannot officially comment on it.
These types of official trips are usually confirmed by either China or North Korea only once the distinguished visitor has safely returned home.
Media reports here say among those accompanying Kim to China is leader Kim Jong Il's brother-in-law, Jang Song Thaek.
Some analysts have described Jang as the likely overseer of the younger Kim, who is in his late 20?s, during any generational transition of power.
The elder Kim, who is 69, is believed to have suffered a stroke two-and-a-half years ago.
Last September, Kim Jong Un was appointed to the second highest military post within North Korea?s only political party and given other senior positions. That was interpreted as the most significant indication that he is poised to eventually succeed his father.
Kim Jong Il also succeeded his father, Kim Il Sung, North Korea?s founder.
In recent months, Pyongyang has made an urgent appeal for international aid. South Korea has said it will only resume significant aid after North Korea apologizes for last year?s sinking of one of its warships and the shelling of a frontier island.
North Korea denies attacking the South Korean naval vessel and says that the island bombardment was an act of self-defense during a provocative South Korean military exercise involving disputed waters.
Portions of this story were found to be incorrect. An update versions has been posted to the VOA website.