Published: Apr 11, 2013 9:40 PM EDT
Updated: Apr 11, 2013 10:39 PM EDT

WASHINGTON (AP) - A U.S. intelligence report concludes that North Korea has advanced its nuclear knowhow to the point that it could arm a ballistic missile with a nuclear warhead, a jarring revelation in the midst of bellicose threats from the unpredictable communist regime.
 
President Barack Obama urged calm, calling on Pyongyang to end its saber-rattling while sternly warning that he would "take all necessary steps" to protect American citizens.
 
The new American intelligence analysis, disclosed Thursday at a hearing on Capitol Hill, says the Pentagon's intelligence wing has "moderate confidence" that North Korea has nuclear weapons capable of delivery by ballistic missiles but that the weapon was unreliable.
 
Rep. Doug Lamborn, R-Colo., read aloud what he said was an unclassified paragraph from a secret Defense Intelligence Agency report that was supplied to some members of Congress. The reading seemed to take Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, by surprise, who said he hadn't seen the report and declined to answer questions about it.
 
In a statement late Thursday, Pentagon press secretary George Little said: "While I cannot speak to all the details of a report that is classified in its entirety, it would be inaccurate to suggest that the North Korean regime has fully tested, developed or demonstrated the kinds of nuclear capabilities referenced" in Lamborn's remarks.