But a Defense Department spokesman later on Thursday cast doubt on whether Pyongyang is fully capable of firing nuclear missiles, as a study dated last month by the Pentagon’s own Defense Intelligence Agency suggested.

The secret assessment – which was mistakenly marked as unclassified and partially revealed at a congressional hearing – said the agency had “moderate confidence” that North Korea is able to launch nuclear-armed ballistic missiles. But it said the weapons would probably be unreliable.

The evaluation was made public by Representative Doug Lamborn as he questioned senior Pentagon officials about North Korea’s nuclear weapons program during a hearing of the House of Representatives Armed Services Committee.

“DIA assesses with moderate confidence the North currently has nuclear weapons capable of delivery by ballistic missiles, however the reliability will be low,” Lamborn said, quoting from a DIA report entitled “Dynamic Threat Assessment 8099: North Korea Nuclear Weapons Program (March 2013).”

Effectively confirming the assessment, a U.S. official said that Lamborn had done nothing wrong in releasing the statement but declined further comment on the study. He said the quotation cited by Lamborn was in a section of the study that had been erroneously marked unclassified.

Lamborn did not say what range the nuclear-capable North Korean missiles might have. Hans Kristensen, a nuclear weapons analyst at the Federation of American Scientists, said one analyst recently claimed nuclear warhead capability for North Korea’s Nodong short- to medium-range missile. It would be able to hit U.S.-based facilities in the region, including South Korea and probably Japan.

U.S. officials tried to play down the DIA evaluation.

Pentagon spokesman George Little said, “It would be inaccurate to suggest that the North Korean regime has fully tested, developed or demonstrated the kinds of nuclear capabilities referenced in the passage.”

A U.S. official said the DIA study was a lower-level assessment that had not been approved by the full intelligence community.

UNABLE TO REACH U.S.

The consensus inside the U.S. government is that North Korea does not yet have a nuclear device that would fit longer-range missiles which conceivably could reach U.S. territories.

“It’s very clear that it cannot at this stage include long-range ballistic missiles because they’re just basically not developed sufficiently yet to be able to do this,” Kristensen said.

All the same, the release of part of the DIA report will likely raise tension on the Korean peninsula where North Korea has stationed as many as five medium-range missiles on its east coast, according to assessments by Washington and Seoul, possibly in readiness for a test-launch that would demonstrate its ability to hit U.S. bases on Guam.

Most observers say Pyongyang has no intention of starting a war that would likely bring its own destruction, but they warn of the risks of miscalculation.

The Defense Intelligence Agency is a Pentagon spy agency that gathers information about the capacity and strategic intentions of foreign militaries.

Greg Thielmann, a former State Department intelligence analyst now with the Arms Control Association advocacy group, said that while he did not have access to the classified material cited in Congress, what was said publicly about DIA’s assessment sounded quite tentative.

“It really says to me that this is a speculative statement,” Thielmann said. “Moderate (confidence) is higher than low confidence but it doesn’t say they know very much.”

He described the DIA statement as a “cautious worst-case assessment.” DM

Photo: A rocket is carried by a military vehicle during a military parade to celebrate the centenary of the birth of Kim Il-sung in Pyongyang April 15, 2012. REUTERS/Bobby Yip