Hyun In-Taek told lawmakers that the government was "watching closely because possibilities cannot be completely ruled out," but said that the chances of an imminent atomic test were "currently low."
Chosun Ilbo, South Korea's biggest-selling newspaper, said Thursday that North Korea appeared to be preparing for a third test, citing an unidentified government source.
US satellites had detected movements of personnel and vehicles at the site where the reclusive communist state carried out its first two nuclear tests in 2006 and 2009, the report said.
But US and South Korean officials said there was no evidence that North Korea was readying such a test.
earlier related reportN.Korea nuclear arms 'most serious threat' to Asia-PacificSeoul (AFP) Oct 22, 2010 - Military leaders from across the globe believe North Korea's nuclear programme poses "the most serious threat" to the Asia Pacific region, officials said at a high-level meeting that wrapped up Friday.
They also agreed on the need to enhance cooperation in maritime security operations against the proliferation of weapons of mass destruction, said General Han Min-Koo, chairman of South Korea's Joint Chiefs of Staff (JCS).
"Participating countries reached a consensus on the fact that the North Korean nuclear programme presents the most serious threat to regional security," Han said at a press conference after the Chiefs of Defence gathering which involved 26 countries.
US Admiral Robert Willard, commander of the US Pacific Command, also said the threat from North Korea's nuclear capabilities was "widely recognised as significant not just to South Korea but region as a whole".
"The next (nuclear) test (by North Korea) would be a very serious matter for the international community and the Republic of Korea (South Korea)," he warned.
Chosun Ilbo, South Korea's biggest-selling newspaper, said Thursday that North Korea appeared to be preparing for a third nuclear test, citing an unidentified government source.
US satellites had detected movements of personnel and vehicles at the site where the North carried out its first two nuclear tests in 2006 and 2009, it said.
But South Korean government officials said there was no concrete evidence that the communist state was readying such a test, saying Seoul and its allies are closely watching developments related to the North's nuclear facilities.
Another atomic weapons test by North Korea would be provocative, US State Department spokesman Mark Toner said Thursday, but added that he could not confirm reports that Pyongyang was preparing for such a test.
The countries represented at the five-day defence meeting included the United States, Russia, Britain, France, Japan, India, Australia, New Zealand and Southeast Asian nations.