North Korean leader Kim Jong-Il told China Friday he was ready to resume six-party nuclear talks without preconditions, as he travelled through the Asian nation, the China's state media said.

Kim, who travels by armoured train and is on his way back from an official visit to Russia, made the comments in a meeting with Chinese State Councillor Dai Bingguo in northeast China's Heilongjiang province.

"The DPRK adheres to the goal of denuclearisation on the Korean peninsula and is ready to fully implement the September 19 joint statement along with all sides," the official Xinhua news agency quoted him as saying.

Kim was referring to a statement signed in 2005, in which North Korea promised to abandon all nuclear weapons and existing atomic programmes.

Pyongyang stormed out of six-party negotiations aimed at disbanding its nuclear arsenal in April 2009, and conducted its second nuclear test a month later.

Since then, it has occasionally stated its desire for an early resumption of the talks involving China, Japan and the United States as well as the two Koreas and Russia, "without preconditions".

On Wednesday, Kim held his first summit with Russian President Dmitry Medvedev at a Siberian garrison, and voiced hopes for the resumption of the so-called six-party nuclear disarmament talks.

The summit ended with a Kremlin announcement that North Korea was ready to resume dialogue without preconditions and abandon atomic enrichment and testing once the six-party talks restarted.

But both the United States and South Korea -- who along with China and Japan make up the other four countries involved in the process -- dismissed the proposal as nothing new.

"If it's true, (it's a) welcome first step, but far from enough... to resume the six-party talks," US State Department spokeswoman Victoria Nuland told reporters.

South Korean officials demanded that the North abandon its nuclear programme before assuming negotiations on the potential lifting of sanctions and provision of international aid for the impoverished republic.

China is the North's sole major ally and a crucial prop for its ailing economy, especially after South Korea severed most ties with Pyongyang last year, accusing it of torpedoing one of its warships and killing 46 sailors.

The six-party forum involves the two Koreas, China, the United States, Russia and Japan.

Earlier this month, Beijing said an early resumption of six-party denuclearisation talks was "in the common interests" of all the countries involved.

The United States has been pressuring China to persuade North Korea to return to the negotiating table and not take further "provocative action".

In November, North Korea launched an artillery and rocket attack on Yeonpyeong island near the tense border with South Korea, which killed two Marines and two civilians.

The attack further worsened relations already under strain from the March 2010 sinking of a South Korean warship, blamed by Seoul on Pyongyang, which denies responsibility.

Earlier Friday, the North Korean leader visited a factory in the city of Qiqihar in Heilongjiang, where residents reported a heavy police presence.

Xinhua said Kim crossed into China by train at the border city of Manzhouli on Thursday.

It is Kim's first visit since May, when he told China he remained committed to the denuclearisation of the Korean peninsula.

Previous trips by Kim to China have been shrouded in secrecy and only officially confirmed by either side after his departure.