North Korea may have nuclear warhead capability, U.S. agency says

WASHINGTON -- A U.S. intelligence agency has concluded that North Korea has the capability to develop nuclear warheads small enough to fit on a ballistic missile, a congressman disclosed Thursday.

Although U.S. experts believe that North Korea cannot hit the U.S. mainland with its missiles, a significant improvement in Pyongyang’s weapons technology would be deeply disconcerting for U.S. policymakers. It would also help explain American measures -- including an emphasis on the U.S. ability to respond with nuclear weapons -- after weeks of warlike rhetoric from Pyongyang.

Regional intelligence officials and analysts say North Korea is poised to launch as many as five missiles from its east coast, but that they did not appear to be in preparation for war. They said the launches were likely to only be part of a military exercise and would not pose a threat to the United States or its allies, Japan and South Korea.

Analysts said the exercise would probably be part of festivities planned to mark the birthday Monday of the country’s late founder, Kim Il Sung, grandfather of the current leader.

At a House Armed Services Committee hearing focused on the budget, Rep. Doug Lamborn (R-Colo.) read from what he said was an unclassified portion of a classified Defense Intelligence Agency study. “DIA assesses with moderate confidence the North currently has nuclear weapons capable of delivery by ballistic missiles. However, the reliability will be low,” it says.

Lamborn said the DIA study was completed last month, but that the conclusion had not been made public.

Pentagon spokesman George Little said he could not address the details of a classified report. However, he added, “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.”

James Clapper, the director of national intelligence, said in a statement that the DIA view is not a formal assessment shared by all U.S. intelligence agencies.

The DIA tends to be more aggressive in its intelligence assessments than the CIA, according to Bruce Klingner, a former CIA analyst on North Korea. He said the DIA has hinted in the past that Pyongyang could mount warheads on its missiles.

The Pentagon announced last month that it plans to augment missile defense systems in Alaska in response to the North Korean threat. The Defense Department also said it will deploy another antimissile system to Guam, which is within range of North Korean missiles.

The Pentagon also sent two long-range B-2 bombers from their base in Missouri last month on a round-trip flight to South Korea as part of a military exercise.

North Korea claimed after its most recent nuclear test in February that its objective was to develop a smaller and lighter warhead with “diverse materials.”

Analysts said the statement indicated that Pyongyang was stepping up its development of a miniaturized warhead that could fit atop one of its long-range missiles, and that the device used enriched uranium as a trigger, rather than the plutonium previously used.

North Korea’s official news agency said the nuclear test was successful. Seismic monitoring systems measured a resulting earthquake of magnitude 5.1, slightly higher than in past tests. But U.S. officials said yield estimates were uncertain.

At a Pentagon news conference last month to announce expansion of the U.S. missile defense systems, Defense Secretary Chuck Hagel did not answer directly when he was asked when North Korea would have intercontinental ballistic missiles armed with nuclear warheads. He said the U.S. goal was to stay ahead of the development of North Korea’s weapons.

David Albright, a nuclear weapons expert with the Institute for Science and International Security, said in February that he believed North Korea has had the capability to mount a plutonium-based warhead on its shorter-range Rodong missiles “for some time,” and was making progress on developing a warhead for an intercontinental ballistic missile.

He said that the U.S. intelligence community has not “been of one opinion” on North Korea’s ability to produce miniaturized warheads. “Key members” of the intelligence community have credited Pyongyang with the ability to produce smaller warheads “for many years,” he said but that conclusion was based on assessment and “not concrete evidence.”

At a different congressional hearing Thursday, Clapper sought to downplay the recent tensions with North Korea. He said tensions were worse in previous episodes in his career, but he underscored how uncertain the intelligence is about North Korea’s new leader, Kim Jong Un.

“We don’t have good detail on the inner sanctum,” he said. “There’s no telling how he’s going to behave. He impresses me as impetuous, [and] not as inhibited as his father became about taking aggressive action.”

Xu Guangyu, a senior military analyst in Beijing, said there was no threat from the missiles likely to be launched in coming days by North Korea. “The grandson is using the missiles to salute his grandfather and celebrate his power,” Xu said.

Nevertheless, Japan and South Korea said they will use Patriot antimissile systems to shoot down any North Korean projectiles that threaten their territory.

Among the missiles that might be launched is a new, as-yet-untested Musudan with an estimated range of up to 2,400 miles, enough to reach the Pacific island of Guam.

South Korean intelligence sources were quoted Thursday as saying satellites had detected two of the missiles and launchers being moved in and out of a shed near the coastal city of Wonsan.

“There are signs the North could fire off Musudan missiles any time soon,” an unidentified intelligence source in Seoul told the state-run Yonhap news agency.

The South Korean officials also predicted possible launches of short-range Scud missiles and medium-range Rodong missiles.

Trying to defuse the tension, the South Korean government suggested negotiations over a jointly run industrial park in Kaesong, just north of the demilitarized zone. North Korea pulled out its 53,000 workers this week, threatening a project that had been one of the crowning achievements of inter-Korean cooperation.

Officials in the North Korean capital, Pyongyang, have been issuing daily predictions about the imminent outbreak of war.

On Thursday, the Committee for the Peaceful Reunification of the Fatherland said that Pyongyang had “powerful striking means” on standby for a launch that would “turn the stronghold of the enemies into a sea of fire.”

But tourists, who flew out Thursday after a two-week trip, said they saw no signs of war preparations or anxiety among the North Korean population.

“Soldiers are working in the fields, planting trees, or just hanging around,” said Kees Wielinga, a Dutch businessman who had returned through Beijing. “There were no civil defense preparations, no mobilization at all.”

Military analysts said the planned launches did not appear to be in preparation for war.

“I worry as much about North Korea unleashing a full-scale war as I do about an asteroid hitting my house,” said Daniel Pinkston, a Seoul-based analyst for the International Crisis Group, a think tank.

“We expect these missiles will fall in the ocean and give the intel people a chance to study their weapons systems.”

Shin In-kyun, who heads an alliance of defense experts based in Seoul, added that North Korea’s leader wants to show his people that he is taking a “bold stance” against the United States and Japan.

In London, meanwhile, foreign ministers from eight of the world’s leading economies denounced North Korea’s bellicose rhetoric “in the strongest possible terms” and warned that they would step up sanctions if the isolated nation conducts another missile launch or nuclear test.

ken.dilanian@latimes.com

david.cloud@latimes.com

barbara.demick@latimes.com

Dilanian and Cloud reported from Washington, and Demick from Beijing. Times staff writer Henry Chu in London, special correspondent Jung-yoon Choi in Seoul and Nicole Liu in The Times’ Beijing bureau contributed to this report.