BEIJING, Dec. 21 (Xinhua) -- Top negotiator of Republic of Korea (ROK) Chun Yung Woo said on Thursday that there is no breakthrough for the six-party talks on the Korean Peninsula nuclear issue, but all sides have nailed down their difference.

    "Identifying differences itself can be seen as positive progress," said Chun when dinning with the U.S. and Japanese top envoys on Thursday evening.

    Chun said the key to the talks lies in whether "substantive progress" will be made.

    U.S. negotiator Christopher Hill said Thursday that the second phase of the talks will end on Friday.

    Hill said the U.S. delegation will hold another one-on-one meeting with the delegation of the Democratic People's Republic of Korea (DPRK) on Friday and leave Beijing on Saturday morning.

    Although the talks are expected to end on Friday, the prospect remains misty.

    The ongoing talks focus on the implementation of the joint statement, under which the DPRK agreed to abandon its nuclear program in exchange for economic aid and security guarantees.

    The talks involving China, the DPRK, the United States, the ROK, Japan and Russia resumed Monday.