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North Korea (search) is looking for an extended delay in resuming negotiations over its nuclear weapons program and even told China there was no point in continuing the six-sided talks at all, a senior U.S. official says.

The talks, which recessed in late June, had been expected to be resumed by the end of September. Hoping to persuade North Korea to halt its program, the Bush administration was willing to offer written assurance that it had no plans to attack, while Japan and South Korea were expected to lay out economic incentives they would offer.

But North Korea has sought one-on-one talks with the United States and has decided to wait until at least after the Nov. 2 presidential elections to start talking again, the U.S. official said Tuesday.

Democratic presidential nominee John Kerry favors direct talks with North Korea about its nuclear program. President Bush has pursued six-party talks involving North Korea's nearest neighbors — China, South Korea, Japan and Russia — as well as the United States to confront North Korea with the aim of halting its development of nuclear weapons (search).

China already has concluded that negotiations would not resume this month as planned, said the official, who spoke on condition of anonymity. The Bush administration is inclined to expect a delay until after the election.

In Moscow, the Russian delegation's leader, Deputy Foreign Minister Alexander Alekseyev, was quoted as telling the Interfax news agency the next round of six-nation talks would not be held this month.

"The Russian side unambiguously believes that it would be correct to hold this round at the end of September, as was decided during the third round in Beijing. But for a series of reasons, it can't be done," Alekseyev said.

Kerry, meanwhile, has accused the Bush administration of letting a "nuclear nightmare" develop by refusing to deal with North Korea when it first took office in 2001.

"North Korea's nuclear program is well ahead of what Saddam Hussein was even suspected of doing; yet the president took his eye off the ball, wrongly ignoring this growing danger," Kerry said in a statement.

U.S. analysts are convinced North Korea is at the brink of making several nuclear weapons. Negotiations became even more urgent with a North Korean blast last week that produced a mushroom cloud near the Chinese border.

The U.S. official characterized as dubious North Korea's explanation that the blast was the demolition of a mountain for a hydroelectric project. For one thing, the blast does not appear to have had the magnitude to demolish a mountain, the official said.

At the same time, he said, the Bush administration has not yet figured out what happened.

China would be the best source of information outside Pyongyang, but so far Chinese officials have not given the Bush administration any evaluation they may have made, the official said.

A State Department spokesman, Adam Ereli, said only that "it will be an issue we will continue to look at closely."

South Korean officials said Tuesday they were trying to verify North Korea's claim that the explosion involved a civilian project.

Meanwhile, even though North Korea has told China it did not plan to resume six-party talks this month, North Korean leader Kim Jong Il (search) told British diplomat Bill Rammell something different, the official said: that North Korea remained committed to resuming talks as planned.

State Department spokesman Richard Boucher said, "People are looking at the calendar and drawing the conclusion that the North Koreans may not fulfill the promise and commitment they made at the last round of talks to have these talks in September."

"At this point, I don't think there is any clear indication from the North Koreans what their intentions are and what their reasons might be," Boucher said.

"It's too early to draw a conclusion on this, but it does appear that the North Koreans have been stalling," he said.