Japan's Kyodo News Agency says the International Atomic Energy Agency (IAEA) is planning to adopt a Chairman's statement expressing deep concern over secret nuclear experiments previously conducted by South Korean scientists.

Quoting a diplomatic source familiar with the issue, the news agency said Thursday that a Chairman's statement by the U.N. nuclear watchdog, though not binding, would deal a heavy diplomatic blow to Seoul.

However, other news sources downplayed the possibility of such a statement being issued, saying the IAEA would unveil its final assessment on the matter in November, when it is expected to announce the results of its investigations into the controversial experments.

The IAEA is set to hold further discussions on the matter around Friday or Saturday.