Signs of difficulty have emerged as parties struggle to coordinate a definitive timetable for working-level nuclear talks.

The talks were originally to be held in the third week of August to lay the groundwork for the fourth round of high-level nuclear dialogue aimed at resolving an international standoff over North Korea's nuclear weapons program.

A government official says while Seoul wants the working talks to be held within this month, host-nation China will have the final say on the matter.

So saying, the official noted the possibility that the working-level meeting may take place next month.

China had earlier sent its Special Envoy to North Korea, Ning Fukui, to Seoul and Tokyo to fine-tune opinions with the two nations, and is now set to discuss matters with Pyongyang to hammer out details of the scheduled talks.