Defense minister Shin Won-sik said signs of an experimental light-water reactor at North Korea’s Yongbyon complex were detected well before the time frame claimed by the international nuclear watchdog.

Speaking to local reporters on Thursday, Shin said outflow of water from the reactor's cooling system was detected in the summer, earlier than mid-October as announced by International Atomic Energy Agency Director General Rafael Grossi last week.

Shin said the reactor is currently testing basic functions as improvements are being made to its equipment and facilities. The minister added that normal operationality is expected by next summer.

Shin said, however, that Pyongyang will more than likely use the facility to generate electricity rather than produce plutonium, in line with the standard use of light-water reactors and correlating to the assertion by the regime.

Any military use of the reactor, the minister said, would probably be a test of the development of a small reactor for use inside a nuclear-powered submarine, but can also be used to produce tritium, an ingredient for hydrogen bombs.

Asked about projections of a provocation ahead of April's general elections in South Korea and the U.S. presidential election next year, Shin said the North is expected to carry out a "direct military provocation" against the South and a "strategic" one against the U.S.