Kim's three-day visit to Beijing - which ended Wednesday but was kept secret until Thursday - was the highest exchange between the two countries in nine years, underscoring a warming of ties after nearly a decade of relative coolness between the communist former allies.
The visit took on added importance, coming just two weeks before Kim meets South Korean President Kim Dae-jung in the first summit between the rival Koreas.
Chinese President Jiang Zemin told Kim that China "welcomes and supports the North Korean and South Korean summit and hopes to see positive progress," a Chinese spokeswoman said.
Jiang is likely to visit North Korea within this year to reciprocate the recent visit to Beijing by the North's reclusive leader Kim Jong-il, local newspapers said on Thursday.
In their early Friday editions, major newspapers, including the Dong-a Ilbo, reported the agreement was struck at a secret meeting between the two leaders in Beijing.
Quoting a senior Chinese Communist Party official, the Hankook Ilbo said Jiang would likely visit Pyongyang in October in time for the anniversary of the North's Labour Party.
A Chinese Foreign Ministry spokeswoman declined to comment.
Highlighting the Beijing visit's significance, Jiang and the six other members of China's ruling Communist Party inner circle met Kim, state media reported. Chinese state television showed Kim and Jiang hugging.
In a telling detail about the different paths their nations have taken, Jiang wore a Western suit and tie. Kim had on a high-collared gray Mao jacket with a badge of his father, revolutionary leader Kim Il Sung, on his lapel.
State-controlled media in both nations described the talks as cordial and friendly. Kim took home a Chinese promise for food and other aid, Chinese Foreign Ministry spokeswoman Zhang Qiyue said. She did not specify the amount that China would give to economically struggling North Korea.
Kim noted the "great achievements" of China's two-decade reform program and said China's rising power and international status show the reforms are "correct," the Chinese government news agency, Xinhua, reported.
North Korea "supports the reform policy pursued by the Chinese side," Zhang quoted Kim as telling Jiang.
While China has prospered under reform, hard-line North Korea has resisted change and sunk into famine and economic collapse. Apparently defending his nation's path, Kim said North Korea "is building a Korean-style socialism according to its specific national conditions," Xinhua said.
The announcement of Kim's visit followed two days of rumors closely followed by diplomats and government officials in Beijing and South Korea.
In one f the visit's more unexpected moments, Kim toured Legend, a respected Chinese computer maker in Beijing's high-tech district of computer and Internet ventures.
The stop showed that Kim "is very interested in computer technology," but not that North Korea would quickly follow Chinese reforms, said Shinya Kato, a Japanese expert on North Korea.
"They are gradually reforming their economy," Kato said. "They are not in a hurry."
Kim, who assumed power in 1994 on the death of his father and whose last known visit abroad was to China in 1983, was accompanied by top Workers Party and military leaders, among them Gen. Jo Myong Rok, his close confidante and political commissar of the Korean Peoples' Army.
China and North Korea, allies during the 1950-53 Korean War, used to describe their relationship as being as close as "lips and teeth." But ties frayed after China opened diplomatic relations with South Korea in 1992.
Relations have warmed over the past year. Kim Yong Nam, head of North Korea's legislature and No. 2 in the communist Workers Party, visited Beijing last June. North Korean Foreign Minister Paek Nam Sun traveled to Beijing in March amid reports of preparations for an official visit by Kim.
Kato, the Japanese analyst, said Kim might have kept his visit quiet to avoid angering South Korea and stealing the thunder of its president, Kim Dae-jung, who "thought that he was going to be the first foreign president to meet Kim Jong Il."
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