North Korean leader Kim Jong-Il has told Chinese envoy Tang Jiaxuan that the communist country would not conduct a second nuclear bomb test, Yonhap news agency said Friday.

The agency quoted an unidentified diplomatic source in Beijing as saying: "Kim was known to have clarified his stance that there will be no additional nuclear test."

"If the US makes a concession to some degree, we will also make a concession to some degree, whether it be bilateral talks or six-party talks," Kim was quoted as telling a Chinese envoy, the mass-circulation Chosun Ilbo reported, citing a diplomatic source in China.

Kim told the Chinese delegation that "he is sorry about the nuclear test," the newspaper reported.

The delegation led by State Councilor Tang Jiaxuan met Kim on Thursday and returned to Beijing later that day ahead of US Secretary of State Condoleezza Rice's arrival in the Chinese capital Friday. China is viewed as a key nation in efforts to persuade the North to disarm, as it is the isolated communist nation's main trading partner.

North Korea has long insisted that the US desist from a campaign to sever its ties to the international financial system. Washington accuses Pyongyang of complicity in counterfeiting and money laundering to sell weapons of mass destruction.

The North has refused since last November to return to the nuclear talks, which also include China, Japan, Russia and South Korea. Pyongyang has sought bolster its negotiating position by a series of provocative actions, test-firing a barrage of missiles in July and performing its first-ever nuclear test Oct. 9.

In Beijing China and the United States pressed North Korea on Friday to return to talks on ending its nuclear arms programme and called for full implementation of UN sanctions imposed on the country after its October 9 atomic test.

The crisis trip by US Secretary of State Condoleezza Rice to east Asia has been overshadowed by speculation that communist North Korea might be about to detonate a second nuclear device.

But Chinese officials suggested that their envoy, sent by President Hu Jintao to Pyongyang earlier this week, had made progress in bringing North Korea back into line.

"Fortunately my visit this time has not been in vain," the envoy, Tang Jiaxuan, said at the opening of his meeting with Rice, referring to his trip to Pyongyang. Reporters were then ushered from the room.

China, a traditional ally of North Korea, is seen as having the greatest potential leverage over its neighbour.

Chinese Foreign Minister Li Zhaoxing said Tang and the North Koreans also discussed how to kick-start stalled talks on Pyongyang's nuclear programmes.

"At least it increased mutual understanding. Everyone discussed how to restart progress in the six-party talks as quickly as possible," Li told reporters.

The six-party talks, which bring together the two Koreas, the United States, Japan, Russia and host China, stalled last November after Washington imposed restrictions on Pyongyang's external financing.

At a joint briefing with Rice, Li appealed for calm and a diplomatic solution to the crisis.

"We hope all relevant parties can maintain cool-headedness, adopt a prudent and responsible attitude and stick to the general direction of a peaceful resolution through dialogue," Li said.

Rice told the news conference after talks with Li that North Korea's nuclear test was "a serious provocation" that posed a threat to peace and security, particularly in east Asia.

"We talked about the importance of the full implementation of (UN resolution) 1718 so we can make certain there is not a transit and trade in illegal materials, dangerous illegal materials, concerning the nuclear programme of the DPRK," she said referring to North Korea by its official acronym.

Rice's visit came one day after Beijing, Pyongyang's biggest backer, sent Tang to lead a mission to North Korea to deliver what US officials said was a "very strong" message.

South Korea's Chosun Ilbo newspaper quoted an unidentified diplomatic source in Beijing as saying Kim told Tang that Pyongyang would return to stalled six-party talks on ending its nuclear programmes if Washington lifts financial sanctions.

Kim also expressed regret to Tang about the difficult position in which the nuclear test had placed Beijing, it said.

US officials tried to lower expectations about the outcome of the meeting and said they did not expect any major announcement such as a return to the six-party talks.

In her meetings with China's president and foreign minister, Rice would try and allay Beijing's scepticism over some elements of financial and weapons sanctions imposed by the United Nations, making clear the United States did not want to escalate tensions, said a senior State Department official travelling with her.

Rice delivered similar messages to the governments of Japan and South Korea on the first legs of her five-day trip.

China in particular fears a heavy-handed approach to inspections of cargo at sea may provoke military confrontations and stoke tensions on the Korean peninsula.

It is also wary about squeezing its food and energy lifeline to Pyongyang, fearing this could lead to an exodus of refugees and even the ultimate implosion of the state.

However, banking sources said some Chinese banks had stopped business dealing with North Korea, a move officials travelling with Rice said would be welcome if true.

The New York Times, citing Chinese analysts, said China would be prepared to step up pressure on the North, including reducing oil shipments, if it refused to return to negotiations or conducted more tests.

In Washington, a senior Bush administration official said the United States was preparing for the possibility not only of a second nuclear test but a further round of missile tests like those Pyongyang conducted in July.

"You have to anticipate they may do more missile launches as well," the official told reporters. "They're clearly trying to get attention and trying to provoke a crisis."