Pascoe's four-day trip comes days after Kim reportedly assured a visiting Chinese official that he is committed to the denuclearisation of the Korean peninsula.

A subsequent Chinese statement extended an invitation China's president for Kim to visit China "when convenient" and calling for the nuclear issue to be "appropriately dealt with".

China meeting

Following the Chinese visit, Kim Kye-gwan, the top North Korean nuclear negotiator, flew to Beijing.

Kim Jong-il, right, hosted a visitng Chinese envoy earlier this week [EPA]

South Korea's Yonhap news agency said he would be holding talks with his Chinese counterparts on steps to restart the stalled aid-for-disarmament talks.

Yonhap, citing unidentified diplomatic sources in Beijing, said the meeting is believed to have focused on the North's demands for UN sanctions to be lifted and for a peace treaty with the US before it will return to talks.

The recent flurry of diplomacy has heightened speculation that there could be a breakthrough in efforts to jump-start the stalled six-nation talks.

The talks, hosted by Beijing, bring together envoys from the two Koreas, the US, China, Russia and Japan.

South Korea's Dong-a Ilbo newspaper on Wednesday said that Kim, the North's nuclear envoy, had flown to China with his English interpreter, and speculated that he may travel on meet his US counterpart Sung Kim in an unidentified third country.

Analysts say the North is feeling the pressure of UN sanctions imposed after its nuclear test last year.

'Imminent resumption'

"This is a sign that the resumption of the six-party talks is imminent," Yang Moo-jin, a professor at the University of North Korean Studies in Seoul, told the AFP news agency.

"The right words must be followed by action. Words by themselves are not sufficient"

P J Crowley, US State Department spokesman

He said the North's top negotiator "is expected to tell Chinese officials about North Korea's disarmament plan in a more concrete manner", probably in return for aid from Beijing.

In Washington, P J Crowley, a US state department spokesman, told reporters on Tuesday that the US supported efforts to restart nuclear disarmament talks, noting that the North seemed to be saying the right things recently.

"The right words must be followed by action. Words by themselves are not sufficient," he said.

"We think that China and the United States see the current situation with respect to North Korea very similarly, and we would hope that the North Korean delegation will receive a very firm message."

North Korea walked away from the talks last year during a standoff over its nuclear and missile programmes.