Japan has unconfirmed information that North Korea is not planning a second nuclear test, Kyodo news agency says.
Kim Jong-il defied pressure to conduct his first nuclear test
North Korean leader Kim Jong-il was believed to have told a Chinese envoy no more tests were planned, Foreign Minister Taro Aso was quoted as saying.
His comment backed an earlier report by South Korea's Yonhap agency, which also said Mr Kim told envoy Tang Jiaxuan that no more tests were planned.
The first test on 9 October sparked world outrage and led to UN sanctions.
"Though it is not confirmed, we have obtained information that [Mr Kim] told Mr Tang the country won't conduct a second nuclear test," Mr Aso was quoted by Kyodo agency as saying.
He added: "I think it is a result of being hard pressed by Japan, the
United States and China these past few days," the agency said.
Mr Tang was sent to Pyongyang by Chinese President Hu Jintao to urge the Stalinist state not to repeat the blast.
China, North Korea's closest ally, has reportedly threatened to cut off vital oil supplies if further tests are conducted.
The BBC's Rupert Wingfield-Hayes in Beijing says the threat to the oil supply demonstrates just how angry and frustrated China now is with its erstwhile friend and ally.
Speaking after his meeting with the reclusive North Korean leader, Mr Tang, who delivered a personal message from Mr Hu, said: "Fortunately, my visit this time has not been in vain".
He did not elaborate, publicly, on the goals of his visit.
NEW UN SANCTIONS
Bans sale to, or export from, N Korea of military hardware
Bans sale or export of nuclear and missile related items
Bans sale of luxury goods
Freezes finances and bans travel of anyone involved in nuclear, missile programmes
Allows inspection of cargo to and from N Korea
Stresses new resolution needed for further action
But China's foreign minister, Li Zhaoxing, later said Mr Tang had spoken to the North Korean leader about how to kick-start six-nation talks on resolving North Korea's nuclear ambitions, which have been stalled since late 2005.
North Korea has stated that it wants US financial and other sanctions lifted before it will consider resuming the talks. Some analysts say North Korea's nuclear test made the talks meaningless.
The US Secretary of State Condoleezza Rice, who is in Beijing as part of an Asian tour to rally support against North Korea, said the financial sanctions would remain in place.
Speaking of Mr Tang's visit, Ms Rice said that he had sent a "strong message" to North Korea over the "seriousness" of its nuclear test.
"The Chinese are emphasising the need for six-party talks to begin again and for the North to re-engage in the talks," Reuters quoted her as saying.
Ms Rice was speaking after talks with Mr Hu, in which she said China promised to be "scrupulous" over inspections on its shared border with North Korea to enforce the UN sanctions.
"The Chinese made the point to us that they are scrupulous about that land border and intend to be scrupulous about that land border," she told reporters.
China backed a resolution in the UN Security Council that imposed sanctions targeting Pyongyang's missile and weapons programmes.
But it baulked at one clause allowing inspections of cargo going to and from North Korea for banned items, fearing it will raise tensions further.
Meanwhile, more than 100,000 people have attended a rally in Pyongyang to celebrate the success of the first underground nuclear test.
Choe Thae Bok, secretary of the Central Committee of the Workers' Party of Korea, told the gathered crowd that the test had been conducted to defend North Korea from the threat of US imperialism and aggression, and to ensure peace on the Korean peninsula, the official Korean Central News Agency reported.