WASHINGTON -- The United States is preparing to significantly raise its estimate of the number of nuclear weapons held by North Korea, from ''possibly two" to at least eight, according to US officials involved in the preparation of a report.
The report, expected to be completed within a month, would reflect a new intelligence consensus on North Korea's nuclear capabilities after that country's decision last year to restart a nuclear reactor and plutonium reprocessing facility that had been frozen under a 1994 agreement. Among the evidence used in making the assessment is a detailed analysis of plutonium byproducts found on clothing worn by members of an unofficial US delegation that was allowed to visit North Korean nuclear facilities several months ago.
The increase in the estimate would underscore the strides North Korea has made in the past year as the Bush administration struggled to respond diplomatically while waging a war against Iraq in an unsuccessful effort to search for such weapons there.
Intelligence officials also have broadly concluded that a separate North Korean uranium-enrichment program will be operational by 2007, producing enough material for as many as six more weapons a year, a US official said.
With Democrat John F. Kerry's presidential campaign planning to highlight the dangers of nuclear proliferation, the leap in Pyongyang's nuclear capabilities during President Bush's tenure could leave the administration vulnerable to charges that it has mishandled the North Korea crisis. Specialists said an arsenal of eight weapons indicates that North Korea could use its weapons to attack neighbors, instead of merely deterring a possible attack.
But some Bush administration officials contend that the new estimate will help pressure North Korea's neighbors to back the US position that Pyongyang's weapons programs must be dismantled without concessions. During a tour of Asia two weeks ago, Vice President Dick Cheney warned that time is running out for diplomacy as an increasingly cash-strapped North Korea might seek to peddle its nuclear technology or fissile material -- including, Cheney said, to terrorist groups.
The estimates are guesswork based largely on circumstantial evidence, and administration officials in several agencies have not agreed on specific numbers.
The Energy Department has pressed for a higher estimate of North Korea's weapons and the Defense Intelligence Agency contends the uranium program will be operational at year's end. But the State Department's intelligence arm has been the most skeptical. The differences in estimates depend in part on determinations about the power and efficiency of the North Korean design.
Work on the report began late last summer after the first round of six-nation talks on the North Korea crisis, when various government agencies sought a unified position on the extent of Pyongyang's programs. Much of the report will not be made public, but its conclusions will guide official statements on North Korean capabilities.
In many ways, the official US estimate of ''possibly two" weapons lags significantly behind private-sector reports.
The International Institute for Strategic Studies in London concluded this year that North Korea's nuclear arsenal could reach four to eight bombs over the next year and increase by 13 bombs a year by the end of the decade.
The Institute for Science and International Security in Washington recently estimated that North Korea has a maximum of eight or nine weapons. ''It's long overdue for them to do something," David Albright, president of the the institute, said of the Bush administration.
Albright said that the January visit of the unofficial delegation -- which included Siegfried Hecker, a former director of Los Alamos National Laboratory -- brought back evidence that North Korea has reprocessed all 8,000 spent fuel rods that had been held in a cooling pond under a 1994 agreement negotiated by the Clinton administration.
In late 2002, Pyongyang expelled international inspectors observing the pond after the United States suspended shipments of fuel oil because, officials said, North Korea had nullified the 1994 deal by having a clandestine uranium program.
In February, CIA director George Tenet told Congress: ''The intelligence community judged in the mid-1990s that North Korea had produced one, possibly two, nuclear weapons. The 8,000 [spent fuel] rods the North claims to have processed into plutonium metal would provide enough plutonium for several more."