South Korea's foreign ministry said on Tuesday that the restart of the nuclear reactor in Yongbyon would be "very regrettable" after the Democratic People's Republic of Korea (DPRK) announced its decision to restart operations at the Yongbyon nuclear facility.

"I watched the (KCNA's) report. It would be very regrettable if the news report is true," foreign ministry spokesman Cho Tai- young told reporters at a regular briefing.

The remarks came after the Korea Central News Agency (KCNA) quoted a spokesman of the DPRK's department for atomic energy as saying that it has decided to refurbish and re-operate the five- megawatt graphite moderated reactor, which was shut down in October 2007 under an agreement at the six-party talks.

The resumption of the reactor operation, which the spokesman said will be made "without delay," would allow the DPRK to extract plutonium from spent fuel rods. The northern neighbor said the restart will contribute to solving the problem of electricity shortage by developing its nuclear power industry in a self- sufficient way.

South Korea's foreign ministry spokesman urged the DPRK to " live up to promises it made in the past and sustain denuclearization on the Korean Peninsula," saying that Seoul will continue to closely watch the developments.