U.N. Secretary-General Ban Ki-moon told CNN's Wolf Blitzer that the agency has no independent information to verify the DIA's assessment.
The DIA has been wrong in the past, producing an assessment in 2002 that formed the basis for arguments that Iraq had nuclear weapons -- a view later found to be incorrect
Confusion over intel's release
The report was "mistakenly" marked as declassified, according to an administration and a defense source. A House Armed Services Committee aide said staffers checked with the DIA to confirm that the passage was not classified before Lamborn read it.
Lamborn told CNN's "AC360" that he acted properly in disclosing it during the hearing.
"Given the seriousness of the threat, this is something that I think people do need to know about," he said.
On Friday, Rep. Buck McKeon, R-California, also backed disclosure of the assessment.
"I have to believe they know what they're doing," said McKeon, chairman of the House Armed Services Committee. "I think it's good for the American people to understand how tenuous this situation is and how important it is for us to have a strong defense."
North Korean missile adjustments
On Thursday, North Korea briefly raised a missile into an upright firing position, stoking concerns that a launch was imminent, a U.S. official told CNN. Later, another U.S. official said it had been tucked back into its launcher.
That could signify that a much-feared launch by the North is less imminent. It could also mean the government was testing the equipment.
The first U.S. official cautioned that raising the untested Musudan missile, which South Korea says has a range of up to 2,175 miles (3,500 kilometers), could have been just a trial run or an effort to "mess" with the United States and its allies.
The believed range means the Musudan could reach Guam, a Western Pacific territory that is home to U.S. naval and air bases, and where the United States recently said it was placing missile defense systems.
The United States and South Korean militaries have been monitoring the movements of mobile ballistic missiles on the east coast of North Korea. Japan has deployed defense systems.
Clapper, the national intelligence director, said Thursday at a House Intelligence Committee hearing that he didn't think Kim had "much of an endgame" other than to get recognition from the world as a nuclear power, which "entitles him to negotiation, accommodation and, presumably, aid."
He reiterated that the nation's "nuclear weapons and missile programs pose a serious threat to the United States and to the security environment in East Asia."
North Korea denied responsibility in a wave of cyberattacks on tens of thousands of computers at South Korean banks and broadcasters last month, the North's state news agency, KCNA, reported Friday.
South Korea this week accused the North of carrying out the March 20 attacks. An official South Korean investigation found that many of the malignant codes employed in the attacks were similar to ones used previously by the North, said Lee Seung-won, an official at the South Korean science ministry.
A spokesman for the General Staff of the Korean People's Army said the allegations are "groundless" and "a deliberate provocation to push the situation on the Korean Peninsula to an extreme phase," according to KCNA.
Friday, North Korea also issued a scathing warning to Japan, saying via KCNA that Tokyo should "stop recklessly working for staging a comeback on Korea, depending on its American master."
Japanese foreign minister spokesman Masaru Sato said such remarks only hurt North Korea.
"Japan would not be pushed around by rhetoric of North Korea," he said.
Late Friday, Japan's Transport Ministry issued a notice requiring Japanese airplanes to report to the U.S. military if they fly near the U.S. military's Kadena base in Okinawa prefecture, the Kyodo News Agency said.
The notice, made at the request of the U.S. military in Japan, is believed to be part of precautions taken against possible North Korean missile launches.