A leading U.S. daily says Washington is preparing to significantly raise its estimate of the number of nuclear weapons held by North Korea, upgrading from its current figure of "possibly two" to at least eight.

Wednesday's Washington Post quoted an intelligence report on the new estimate on Pyongyang's suspected nuclear arsenal.

The paper said intelligence authorities are expected to complete the report within a month, which would reflect a new intelligence consensus on North Korea's nuclear capabilities.

The paper added that intelligence officials have also broadly concluded that North Korea's uranium-enrichment program will be operational by 2007, producing enough material for as many as six additional atomic weapons a year.

But the paper added that the estimates are guesswork based largely on circumstantial evidence and government officials in several agencies have yet to agree on specific numbers.

The White House downplayed the report but has not denied it.