The United States consulted Wednesday with its Asian and Russian negotiating partners even as it seemed at a loss over how to deal with North Korea's defiance of a landmark nuclear disarmament deal.

The International Atomic Energy Agency (IAEA) said that North Korea had kicked out its inspectors from the Yongbyon nuclear plant, removed its surveillance equipment there, and planned to reintroduce nuclear material.

It was the latest defiant step from North Korea toward the United States, China, South Korea, Japan and Russia -- its partners in the six-party negotiations that produced the aid-for-nuclear disarmament deal last year.

"We strongly urge the North to reconsider these steps and come back immediately into compliance with its obligations as outlined in the six party agreements," said White House spokesman Gordon Johndroe.

"The North Korean actions are very disappointing and run counter to the expectations of the members of the six party talks and the international community," he said on the sidelines of the UN General Assembly in New York.

Under the six-country pact, North Korea agreed to disable and dismantle key nuclear facilities and allow UN atomic inspectors to return, in return for one million tonnes of fuel aid and its removal from a US list of terrorist states.

But North Korea announced last month it had halted the process in protest at Washington's refusal to drop it from the US blacklist of countries supporting terrorism, as had been promised.

Washington says the North must first accept strict outside verification of the nuclear inventory that Pyongyang handed over in June.

The latest North Korean moves against the IAEA, the Vienna-based UN nuclear watchdog, "will only deepen their isolation," US Secretary of State Condoleezza Rice warned here.

But, when asked by a reporter "what is going on exactly in North Korea?" Rice declined to answer.

In an interview Tuesday with CNBC television, Rice figuratively threw up her hands when asked whether the reported poor health of North Korean leader Kim Jong-Il was hurting the negotiations.

"Something is going on in North Korea. I don't think any of us know precisely what. We are reading all of the reports that you've talked about," Rice said in the interview that the State Department released Wednesday.

Christopher Hill, her chief negotiator with North Korea, acknowledged Monday that the troubles in the negotiations may be linked to South Korean intelligence leaks that Supreme Leader Kim Jong-Il, 66, has suffered a stroke.

"It's hard to tell," said the assistant secretary of state for east Asian and Pacific affairs.

However, Hill dismissed suggestions that the negotiations with North Korea -- once spurned by President George W. Bush who lumped Pyongyang in the "axis of evil" with Iraq and Iran -- were now unraveling.

"They've been staking out some very tough negotiating positions ... so yes, the negotiating process does continue," Hill said.

Nor was Rice giving up on a legacy of nuclear non-proliferation in Asia.

"By no means," Rice said when a reporter asked if the negotiations were dead. "We have been through ups and downs in this process before but I think the important thing is this is a six-party process."

Both Rice and Hill have been holding an intensive series of talks with their counterparts from South Korea, China, Japan and Russia.

"We'll maintain open lines of communication not only with all of our partners in this process but also the North Koreans to make it clear to them that this would be an unfortunate step that they would take," Rice's spokesman Sean McCormack told reporters late Wednesday.

After Rice's talks with her Russian counterpart Sergei Lavrov, both sides tried not to let their row over the war last month in Georgia undermine their common interests in checking Iran's and North's Korea's nuclear programs.

However, Lavrov indicated there could be fallout until emotions cool.

South Korean Prime Minister Han Seung-soo said here Wednesday that North Korea's actions were "very unfortunate" but expressed cautious optimism that China and the other parties would revive the disarmament process.