South Korean officials have said there have been continual movements of personnel and vehicles at North Korea's main nuclear test site, but ruled out the possibility that the country is preparing its third atomic bomb test anytime soon.
The assessment came shortly after the mass-circulation Chosun Ilbo newspaper reported that Pyongyang may be preparing another nuclear test, citing "brisk" activities at its atomic test site in the north-eastern county of Kilju.
The paper, citing an unidentified South Korean government source, said a US spy satellite detected such activities and that North Korea could detonate a nuclear device in three months.
The North may have intentionally let those activities be detected by the US and South Korean authorities to force them to soften hardline policies and to wrest concessions and aid, the paper said.
The communist country may also be preparing a bomb test to bolster its military capability amid moves to transfer power from leader Kim Jong Il to his third and youngest son, Kim Jong Un, it said.
South Korean officials, however, denied that the North was preparing a nuclear test soon, saying personnel and vehicle movements have been continuously detected for more than a year at the site, where the North conducted two bomb tests in recent years. One official said the movements at the site could be seen as maintenance.
The other official, from the Defence Ministry, noted that South Korean and US authorities have been keeping a close watch on North Korean nuclear facilities.
The US military command in Seoul said it could not comment on the Chosun Ilbo report.
North Korea carried out its first-ever nuclear test in 2006 and the second, more powerful test blast last year, inviting widespread international sanctions.
The country walked out of six-nation disarmament talks on its nuclear programme last year to protest international condemnation of its prohibited long-range rocket launch. The country has recently expressed its willingness to rejoin the talks - involving the two Koreas, the United States, China, Russia and Japan.