"Admittedly, there are some differences among the various sides on the agenda and operating mechanism for the working group," foreign ministry spokesman Kong Quan said.

"I'm not in a position to give you details. The various sides are still in discussions and consultations."

Kong declined to say whether US Vice President Dick Cheney's just-ended visit to China had helped push forward the process of organizing a third round of six-nation talks.

The talks involve China, Japan, North and South Korea, Russia and the United States.

"I hope that Vice President Cheney's visit to China, through the exchange of views between China and the United States, will be helpful to the early implementation of the consensus reached at the second round of six-party talks not long ago," Kong said.

At the last round of talks in Beijing in February all sides agreed to set up the working group to make preparations for a third round of six-party discussions.

Kong said Chinese leaders had told Cheney that Washington and Pyongyang should both be flexible and practical.

"Through this visit (Cheney's) ... the Chinese side expressed that during the process of resolving this issue, both sides face differences, even serious differences, and should show a practical and flexible attitude," Kong said.

"Only through this practical and flexible attitude can the working group be set up, to hold meetings of the working group and to make preparations for the third round of six-party talks."

The first two rounds of talks hosted by China failed to narrow differences over a US demand for the complete dismantling of Pyongyang's nuclear programs.

WAR.WIRE