In an interview with the Council on Foreign Relations think tank that was released Friday, Rice said the six-party talks broke down this month when North Korea balked at a written plan to close "loopholes" in the verification plan.

Rice said "we have negotiated a verification protocol to which they've agreed" during private talks US negotiator Christopher Hill held with his counterpart Kim Kye-Gwan in North Korea in October.

"Unfortunately, some of the clarifications that they made to us privately that needed to be made so that there were no loopholes in that verification protocol, they refused to write down," Rice said.

"And that's where things broke down," the US chief diplomat said, referring to the collapse of the six-party talks in Beijing earlier this month.

"But it also has been a value because the North Koreans are in a situation in which they are confronting Russia, China, the United States, South Korea, and Japan so that they can't just make this a bilateral problem with the United States," Rice said.

She added that North Korea's five partners still had diplomatic leverage under a 2007 landmark deal in which North Korea agreed to dismantle its weapons-grade plutonium programs in exchange for energy aid.

"And the fuel oil shipments that they need, they need not just from the United States but also from South Korea, since South Korea has made clear that their relationship with North Korea depends in part on how denuclearization goes," Rice said.

She also praised the six-party negotiations as having led not only to a halt in plutonium production, but also to the shutdown of the nuclear reactor, the destruction of a cooling tower and the disablement of many activities.

And despite the current breakdown, the negotiations will make headway, Rice predicted.

"I think that within the context of the six-party talks, you ultimately will get a verification protocol that allows us to deal with a lot of very troubling activities," she said.