North Korean leader Kim Jong-Il met President Hu Jintao during his visit to China and stressed the need to preserve their countries' friendship for the "rising generation", state media said Monday.

Analysts speculated that Kim, 68, visited his country's main ally and benefactor to seek support for an eventual transfer of power to his youngest son Jong-Un.

The August 26-30 trip was shrouded in secrecy until Kim's train crossed the border, when the North's Korean Central News Agency (KCNA) and China's Central Television carried their first reports on it.

The Chinese TV station quoted Kim as telling Hu his nation was willing to return to nuclear disarmament talks and reduce tensions in northeast Asia, but KCNA made no mention of such remarks.

The North's agency instead focused heavily on the symbolism of Kim's trip to sites linked to his late father and founding president Kim Il-Sung, a guerrilla fighter against Japan's 20th century colonisation of Korea and northeast China.

Analysts saw this as a bid to confer legitimacy on another father-to-son succession.

The Swiss-educated Jong-Un, believed aged around 27, could be named to a senior post when the North next month holds its first meeting for decades of key ruling communist party delegates.

Hu, at a welcoming banquet last Friday in the northeastern city of Changchun, was quoted by KCNA as wishing "a signal success" to the meeting in the first half of September.

Kim, in his banquet remarks, referred to his father's "hard-fought struggle against the Japanese imperialists" in northeast China.

"With the international situation remaining complicated, it is our important historical mission to hand over to the rising generation the baton of the traditional friendship passed over by the revolutionary forerunners of the two countries as a precious asset so as to carry it forward through generations," he was quoted as saying.

KCNA did not list Jong-Un as among the members of Kim's delegation, but some South Korean media reports have said he accompanied his father.

Kim suffered a stroke in August 2008 and since then has speeded up plans for a power transfer in the hardline communist state.

Chinese television showed Kim, wearing his trademark light brown suit, looking slightly emaciated and limping slightly.

KCNA confirmed earlier reports by South Korea's Yonhap news agency that Kim visited a Jilin school where his father studied from 1927-29, and was "overcome with deep emotion".

He also toured Changchun and Harbin, among other places, the agency said.

"Kim Jong-Il is making a pilgrimage to all these places to showcase that the upcoming power transfer to Jong-Un is an act of following Kim Il-Sung's legacy," Yang Moo-Jin, of Seoul's University of North Korean Studies, told AFP earlier in the day.

Chinese television quoted Kim as saying that North Korea's stance on adhering to the denuclearisation of the Korean peninsula was unchanged, and the country "is not willing to see tensions on the peninsula".

Kim pledged to remain in close consultation with China and hoped for the "early resumption" of six-party nuclear disarmament talks that also include South Korea, the United States, Japan and Russia, it said.

The two leaders discussed the March sinking of a South Korean warship that left 46 sailors dead and a subsequent United Nation's statement condemning the incident, the Chinese report said.

An international panel backed by South Korea has blamed North Korea for the sinking, but Pyongyang has adamantly denied involvement.

Footage showed a stern looking Hu urging Kim to push forward economic reforms and modernisation in North Korea.

China hosts the six-party talks which began in 2003. The North walked out in April 2009 and staged its second atomic weapons test a month later.

As preconditions for returning, it wants an end to sanctions and a US commitment to hold talks about a peace treaty formally ending the 1950-53 war.