White House casts doubt on North Korea's nuclear arms

White House spokesman Tony Snow speaks to media. Picture / Reuters

WASHINGTON - The White House today tried to raise doubts about the strength of North Korea's nuclear programme and sought to play down the significance of its reported test of an atomic weapon.

Two days after North Korea reported detonating a nuclear weapon, US intelligence experts still were unable to conclude whether this in fact happened given the relatively small yield of the underground blast.

North Korea has suddenly emerged as an issue in the November 7 congressional elections, with Democrats seeking to blame President George W. Bush for a failure of international diplomacy. They are calling for a shift in strategy to include direct engagement with North Korea, which the White House has ruled out.

White House spokesman Tony Snow said it would take more time, possibly days, to come to a conclusion on whether a nuclear device had been detonated. He said there was a "remote possibility that we'll never know."

Last week, after Pyongyang said it planned to test a nuclear weapon, the Bush administration was adamant it would view such a move as unacceptable.

On Tuesday, Snow insisted Washington wants a diplomatic outcome and refused to discuss the military option.

He sounded a note of suspicion about whether North Korea detonated a nuclear device, telling reporters that Pyongyang was making the claim only two years after expelling international weapons inspectors. His implication was that it would be hard to advance to weapons that soon.

"What's interesting here is that if there was a nuclear test, ask yourself: They just unlocked Pyongyang a couple of years ago. You seriously believe that they have actually done everything within two years? You could have something that is very old and off the shelf here as well," Snow said.

Other officials said it was unlikely North Korea tried to create the impression of a nuclear test with conventional explosives.

"The working assumption in the intelligence community is that it was a nuclear test that didn't go well," said a US official, who asked not to be identified because he was not authorized to speak publicly about the issue.

Seismic data collected after Monday's explosion suggest the blast could have equalled as little as 200 tonnes of conventional explosives such as TNT, an intelligence source said.

That would be significantly smaller than the several hundred tonnes to one kilotonne of yield initially suggested by US officials on Monday.

"I'd go in the direction of 200 tonnes. That's what's suggested by the seismic readings," the source said.

The nuclear weapon the United States exploded over Hiroshima, Japan, in World War Two was about 12.5 kilotonnes.

Pentagon spokesman Bryan Whitman said officials would use a range of means besides seismic data to try to draw a conclusion about the North Korean explosion, including some he would not discuss.

"There is a possibility that particulate fallout is detectable and then there's a variety of other intelligence means to determine the veracity of the allegation of the tests that they conducted."

Bush on Monday called North Korea's announcement it had carried out a nuclear test a threat to international security.

Snow did not back away from that position, saying North Korea's intention to develop a nuclear weapon in defiance of international pressure was a dangerous predicament that needed to be addressed through international diplomacy.

But asked if he considered the reported test a big deal, Snow replied, "No, I think it's an important deal" and noted that "there are a lot of ifs, aren't there?"

The White House comments were similar to doubts raised about North Korea's missile launches in early July after one of the missiles, a Taepodong-2, which some analysts say is capable of hitting the United States, failed after 40 seconds.

- REUTERS