China has expressed hope that Seoul's recent revelation of its previous extraction of uranium and plutonium will not hamper efforts to open six-way nuclear talks by the end of this month.

A Chinese Foreign Ministry spokesman, Kong Quan, stressed in a news briefing Thursday that suspicions surrounding Seoul's past secret experiments should be fully resolved. Kong also called on the participants of the six-party nuclear talks to have patience on the issue, stressing the need to hold the multilateral discussions within this month as previously agreed.

Earlier on Thursday, Seoul admitted that an experiment carried out at a research-purpose reactor more than 20 years ago produced a minimal amount of plutonium.

The revelation comes on the heels of Seoul's confession last week that it had conducted a one-time experiment four years ago that led to the separation of two-tenths of a gram of uranium.

Highly enriched uranium and plutonium are the two main ingredients of nuclear bombs.