US Secretary of State Condoleezza Rice said on Monday that the United States was prepared to return to the six-party talks "without precondition."

"We've said many times that we are prepared to return to the talks without precondition and that holds," Rice told reporters before she kicks off Asian trip to Japan, South Korea and China today.

Rice urged North Korea to return to the six-party talks, involving the United States, North Korea, South Korea, China, Japan and Russia, that began in August 2003.

"We must remind North Korea that a positive path remains open to it through the six-party talks," Rice said, noting "Now, we want very much to have talks that are actually going to lead some place.

Rice also reiterated US call for North Korea to give up nuclear arms, saying "if it makes the strategic choice to dismantle its nuclear weapons completely, verifiably and irreversibly, an entirely new and better future would be open to it and to its people."

North Korea claimed it conducted a successful nuclear test on Oct.9. It also "totally rejects" a resolution unanimously adopted Saturday by the UN Security Council on its nuclear test.

The six-party talks have been stalled since September last year when North Korea boycotted US financial restrictions aimed at Pyongyang.

In last September, Pyongyang agreed in principle to give up its nuclear weapons program in exchange for aid and security and diplomatic guarantees.

Also on Monday, US National Intelligence Director John Negroponte's office said air samples gathered last week contain radioactive materials that confirm North Korea conducted an underground nuclear explosion.

In a short statement posted on its website, Negroponte's office also confirmed that the size of the explosion was less than 1 kiloton, a comparatively small nuclear explosion. Each kiloton is equal to the force produced by 1,000 tons of TNT.

The statement from Negroponte's office provides the first official confirmation from the United States that a nuclear detonation took place, as Pyongyang has claimed.

(Xinhua News Agency, China Daily October 17, 2006)