North Korean leader Kim Jong-Un
North Korean leader Kim Jong-UnAFP photo

North Korea has the capacity to make a nuclear warhead small enough to fit on a ballistic missile, according to a new assessment by the Pentagon’s intelligence arm.

The assessment by the Defense Intelligence Agency (DIA) said the weapon would have “low reliability,” but the disclosure Thursday during a congressional hearing is likely to raise fresh concerns about North Korea’s capabilities and intentions, reported The Washington Post.

Rep. Doug Lamborn (R-Colo.) read what he said was an unclassified section of the DIA report while questioning Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, during a session of the House Armed Services Committee.

Lamborn said DIA had concluded “with moderate confidence” that Pyongyang “has nuclear weapons capable of delivery by ballistic missiles, however the reliability will be low.”

Nuclear weapons experts said the assessment is the most specific attributed to the U.S. government on North Korea’s ambitions to develop a nuclear weapon that could reach U.S. troops deployed in the region.

“This is the clearest, most direct statement that North Korea has a miniaturized warhead,” Jeffrey Lewis, a North Korea expert at the James Martin Center for Nonproliferation Studies, told The Washington Post. He said, however, that is “consistent with a series of statements that have been made in the past” by U.S. government officials.

The disclosure comes amid growing concerns that North Korea could make good on its promise to go to war with its neighboring nemesis, South Korea. A new armed conflict on the Korean Peninsula has the potential to draw in the United States, which has a security cooperation agreement with Seoul.

A U.S. official said on Tuesday that the Obama administration calculates that North Korea may test fire mobile ballistic missiles at any time.

In his first remarks since the recent outbreak of tension, President Obama Thursday called on North Korea to end its belligerence. Obama also pledged to take “all necessary steps” to protect the United States from any North Korean aggression.

“Now is the time for North Korea to end the kind of belligerent approach that they’ve been taking and to try to lower temperatures,” Obama said after a meeting with U.N. Secretary-General Ban Ki-moon.

On Wednesday, Defense Secretary Chuck Hagel stated bluntly that North Korea’s most recent threats “present a real and clear danger.”

U.S. intelligence officials said Thursday the latest tensions appear to be driven by Kim Jong Un’s interests in showing he is firmly in control of North Korea, not in a real interest in provoking war. They cautioned, however, that discerning the young leader’s intentions is difficult. Kim took power in December 2011 after the death of his father and U.S. officials have only limited evidence to assess his thinking.