WASHINGTON — A new assessment by the Pentagon's intelligence arm has concluded for the first time, with "moderate confidence," that North Korea has learned how to make a nuclear weapon small enough to be delivered by a ballistic missile.
The assessment by the Defense Intelligence Agency, which has been distributed to senior administration officials and members of Congress, cautions that the weapon's "reliability will be low," apparently a reference to the North's difficulty in developing accurate missiles or, perhaps, to the huge technical challenges of designing a warhead that can survive the rigors of flight and detonate on a specific target.
The existence of the assessment was disclosed Thursday by Rep. Doug Lamborn, R-Colo., three hours into a budget hearing of the House Armed Services Committee with Defense Secretary Chuck Hagel and the chairman of the Joint Chiefs of Staff, Gen. Martin E. Dempsey.
Thursday evening, however, Pentagon press secretary George Little issued a statement that sought to qualify the conclusion of the Defense Intelligence Agency, which has primary responsibility for monitoring the missile capabilities of adversary nations but which a decade ago was among those that argued most vociferously — and incorrectly — that Iraq had nuclear weapons.
"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," Little said. "The United States continues to closely monitor the North Korean nuclear program and calls upon North Korea to honor its international obligations."
Nonetheless, outside experts said the report's conclusions could help explain why Hagel has announced in recent weeks that the Pentagon was bolstering long-range antimissile defenses in Alaska and California and rushing another antimissile system to Guam.
The disclosure of the Defense Intelligence Agency's assessment came on the same day that the director of national intelligence, James R. Clapper, sought to tamp down fears that North Korean rhetoric could lead to an armed clash with the United States, South Korea and regional allies, and a high South Korean official called for dialogue with North Korea.
U.S. Secretary of State John Kerry, meanwhile, was scheduled to arrive in Seoul today and then travel to China and Japan. His two principal goals are to encourage China to use its influence to persuade North Korea to abandon its nuclear weapons program and to reassure South Korea and Japan that the United States remains committed to their defense.