"At the moment we have no information that would confirm such reports," a spokesman at Russia's foreign ministry said.

"Such information appears regularly in the foreign media but so far no reports of this kind have been confirmed," the spokesman told AFP.

"We believe that given the need to resolve the situation on the Korean peninsula, inflaming things is counterproductive," he said.

ABC television network said Thursday that the communist state may be preparing an underground nuclear test, quoting US officials.

A senior military official told ABC that an unidentified US intelligence agency had recently observed "suspicious vehicle movement" at a suspected North Korean test site.

The activity included the unloading of large reels of cable outside an underground facility called Pungyee-yok in northeast North Korea, it said.

ABC said cables can be used in nuclear testing to connect an underground test site to observation equipment.

An imminent nuclear test was predicted in North Korea last year but no test occurred.

ABC said underground nuclear tests are "notoriously difficult" to detect ahead of time and noted that the United States had failed to predict nuclear tests by India and Pakistan in 1998.

North Korea claims to have built nuclear weapons and sparked international alarm last month by test-firing seven ballistic missiles.