The U.S. probe of the North Korean records is to focus on the amount of plutonium - a key nuclear bomb ingredient - that the North has produced from spent fuel from the Yongbyon reactor. The reactor has been shut down and is being disabled under last year's disarmament agreement between the North and its five interlocutors: the U.S., China, Russia, South Korea and Japan.
Two diplomats, speaking separately to the AP recently, said that Assistant Secretary of State Christopher Hill agreed to the plan with Chinese officials and Mohamed ElBaradei, chief of the International Atomic Energy Agency, in the past two weeks. Hill is Washington's top North Korea nuclear negotiator.
With the North mistrustful of the U.N.-based agency even before it kicked out IAEA inspectors and then unilaterally abrogated its Nonproliferation Treaty membership in early 2003, China was chosen as a go-between, they said. Beijing is the North's closest ally.
Both diplomats follow the North Korean nuclear issue. They demanded anonymity because their information was confidential.
One of the diplomats said the U.S. considered the use of IAEA resources and personnel helpful in cross-checking the information provided to Washington by the North. The documents were handed over to Sung Kim, the U.S. State Department's top Korea specialist, during a three-day visit to Pyongyang that ended May 10.
As well, he said, both Washington and the IAEA hoped that getting the agency involved would be the start of the process that would ultimately result in Pyongyang returning to the Nonproliferation Treaty fold.
He said that any such sharing of the information with the agency was conditional on agreement by the North - something that had yet to happen. Still, he speculated that Pyongyang would concur because it was interested in ultimately resuming its IAEA membership as one step in ending its international isolation.
The diplomat also said that the agency had very little documentation on the Yongbyon reactor - something that a former senior U.S. nonproliferation official expressed surprise about.
John Bolton, who has served as U.S. ambassador to the United Nations and U.S. undersecretary of state in charge of the North Korean nuclear dossier, said Sunday the fact that the agency had no separate documents to cross-check with the information given Washington could allow Pyongyang to "commit fraud."
"If the IAEA has never had (any) ... documentation, that could make it entirely possible that North Korea could falsify" information about how much plutonium the reactor produced, allowing it to hide undeclared amounts of the substance that can be used as the fissile material in nuclear warheads, he told the AP.
A U.S. State Department outline of the North Korean record issued on their receipt earlier this month said they date to 1986 and were expected to cover reactor operations at three rounds of nuclear reprocessing activity at Yongbyon.
Among other details, the documents are expected to shed light on how many plutonium-packing nuclear weapons the North could produce. Past experts' estimates have put that number at around 13.
North Korea said it needed a strong deterrent to ward off a possible U.S. invasion and exploded a nuclear device in 2006 before agreeing to stop its nuclear weapons program in exchange for economic and political concessions from Asia and the West.
The nuclear standoff began in late 2002 when the U.S. accused the North of seeking to secretly enrich uranium in violation of a 1994 disarmament deal.
In late 2003, the North began negotiations over its nuclear program with the U.S., China, Japan, Russia and South Korea. As talks stalled, North Korea set off its underground nuclear test blast.
Renewed talks led to a disarmament deal in February 2007 that has been plagued by delays.