WASHINGTON • US intelligence agencies believe North Korea has increased production of fuel for nuclear weapons at multiple secret sites in recent months, and may try to hide these while seeking concessions in nuclear talks with Washington, NBC News cited American officials as saying.
In a report last Friday, the network said what it described as the latest US intelligence assessment appeared to go counter to sentiments expressed by President Donald Trump, who tweeted after an unprecedented June 12 summit in Singapore with North Korean leader Kim Jong Un that "there is no longer a nuclear threat from North Korea".
NBC quoted five unidentified US officials as saying that in recent months, North Korea had stepped up production of enriched uranium for nuclear weapons, even as it engaged in diplomacy with the US.
The network cited US officials as saying that the intelligence assessment concludes that North Korea has more than one secret nuclear site, in addition to its known nuclear fuel production facility at Yongbyon.
"There is absolutely unequivocal evidence that they are trying to deceive the United States," NBC quoted one official as saying.
NBC also quoted a senior US intelligence official as saying that North Korea's decision ahead of the summit to suspend nuclear and missile tests was unexpected and the fact that the two sides were talking was a positive step.
But, he added: "Work is ongoing to deceive us on the number of facilities, the number of weapons, the number of missiles... We are watching closely."
Dr Jeffrey Lewis, director of the East Asia Nonproliferation Programme at California's Middlebury Institute of International Studies, said there were two "bombshells" in the NBC report.
He said it had long been understood that North Korea had at least one undeclared facility to enrich nuclear fuel aside from Yongbyon.
"This assessment says there is more than one secret site. That means there are at least three, if not more sites," he said.
Dr Lewis said the report also implied that US intelligence had information to suggest North Korea did not intend to disclose one or more of the enrichment sites.
"Together, these two things would imply that North Korea intended to disclose some sites as part of the denuclearisation process, while retaining others," he added.
US Secretary of State Mike Pompeo has said he would likely go back to North Korea before long to try to flesh out commitments made at the Trump-Kim meeting.
Last Thursday, the Financial Times quoted US officials as saying that Mr Pompeo plans to travel to North Korea this week, but the State Department has declined to confirm this.
Mr Trump on June 23 renewed sanctions on North Korea, citing an "extraordinary threat" from its nuclear weapons - just 10 days after tweeting on June 13 that there was no risk from Pyongyang.