The media's watchful gaze

On Thursday, the first day of his visit, Kim went to Yuwen Middle School in Jilin city of the province, where his father, North Korean founder Kim Il-sung, went to school in the 1920s, Reuters reported.

The Chosun Ilbo newspaper and Yonhap both reported that Kim was believed to have met President Hu in Changchun on Friday.

On Saturday, Kim toured an agriculture exhibition site and Jilin Agricultural University in Changchun, Yonhap said.

Speculation also persisted on the aim of Kim's visit, which was believed to be related to power succession, perhaps to introduce his youngest son, Kim Jong-un, to Chinese leaders.

Reuters cited an unidentified source as saying Kim Jong-il was accompanied by his youngest son in the trip to seek Beijing's approval of plans for his son to eventually succeed him.

But Cui Zhiying, a professor specializing in the Korean Peninsula at Tongji University, ruled out speculation about China's involvement in discussions about the succession.

"The succession of North Korea leaders is their domestic affair. China will not intervene in the domestic affairs of its neighboring country," he said

Kim's visit came at the time when North Korea has expressed a willingness to return to the Six-Party Talks on denuclearization of the Korean peninsula, which have been stalled since 2008.

It also came as a surprise, especially as it coincided with a visit to Pyongyang by former US president Jimmy Carter, who returned home Friday with an American, Aijalon Mahli Gomes, who was sentenced in April to eight years in a North Korean prison for entering the country illegally.

Lü Chao, director of the North and South Korea Research Center at the Liaoning Academy of Social Sciences, expressed his surprise about Kim's missing of a meeting with Carter.

"Carter has a good reputation in North Korea. Kim has met him before. But perhaps Kim missed this meeting on purpose to show his toughness and send a message that it will not bow to US pressure after a series of military drills between the US and South Korea," he said.

Editorials in South Korea media expressed concern about Kim's visit, fearing China may back the North and go against the South.

But Lü called this "a distortion of Chinese foreign policy."

"Building friendship between China and North Korea is for the sake of stability of Northeast Asia and for the benefit of all countries," Lu said.