BEIJING, Oct 25 (Reuters) - North Korea's leader Kim Jong-il told Chinese Vice Premier Li Keqiang that a moribund 2005 deal should be the basis for fresh talks about Pyongyang's nuclear programme, Chinese state media reported, leaving unanswered a key question on uranium enrichment.
The United States and South Korea insist that the North must immediately halt its uranium enrichment programme, which it unveiled last year, as a precursor to restart regional talks that offer economic aid in return for denuclearisation.
Kim's latest offer of fresh nuclear negotiations came as Washington said it had narrowed differences with North Korea on issues standing in the way of a new round of multilateral nuclear talks.
In his meeting with Li, Kim repeated that North Korea is willing to return to six-party talks -- also involving Russia and Japan -- that it walked out of more than two years ago.
But his published comments did not address Pyongyang's uranium enrichment activities, a key obstacle to talks.
"Kim said the DPRK hopes the six-party talks should be restarted as soon as possible," said the Xinhua news agency report on Tuesday of the meeting between Kim and Li in North Korea on Monday night.
The DPRK is the Democratic People's Republic of Korea -- the North's official name.
"All the six parties should fully implement the September 19 joint statement, signed by them in 2005 in Beijing, on the principle of simultaneous action," Kim said, according to the report.
The North's uranium enrichment programme, which opens a second route to make an atomic bomb along with its plutonium programme, is not specifically referred to in the 2005 agreement.
However, Seoul and Washington argue uranium enrichment falls under the broader term "existing nuclear programmes", which the 2005 deal says must be stopped.
Pyongyang states it is willing to discuss the issue once six-party talks resume, but Seoul and Washington say there will be no talks until uranium enrichment is stopped. They say any halt must be verified by international nuclear inspectors.
The United States, South Korea and their allies have been sceptical of North Korea's recent assertions that it stands ready to return to the six-party talks, saying Pyongyang has reneged on past disarmament pledges.
The talks and the embryonic agreement were a diplomatic trophy for Beijing. But North Korea walked out of the negotiations more than two years ago after the United Nations imposed fresh sanctions for a long-range missile test. The following month Pyongyang conducted a second nuclear test.
The North says its uranium enrichment programme is designed to produce power, and argues that the 2005 agreement respects its right to peaceful uses of nuclear energy.
In Geneva, Stephen Bosworth, the U.S. special representative for North Korea, said the two sides "narrowed some differences but we still have differences that we have to resolve".
Throughout the regional turbulence, Beijing has stood by its ally, North Korea, which it sees as a buffer against the influence of the United States and its allies. But China has also tried to preserve ties with South Korea, and to revive the stalled talks on North Korean nuclear disarmament.
Li, 56, is the favourite to become premier from early 2013, when Wen Jiabao will step down. He will visit South Korea after his trip to the North. (Reporting by Chris Buckley in BEIJING and Jeremy Laurence in SEOUL; Editing by Paul Tait)