As the US continues to move forward on diplomatic negotiations with North Korea, assessments from US intelligence agencies and several reports from satellite imagery analysts emerged this week providing evidence that Pyongyang is continuing to expand weapons production capability, which Washington says poses a threat to the US and its allies in Asia.

Some of the reports suggested that the Kim regime was expanding weapons production facilities even as it made tentative statements promising to "denuclearize" in the run up to the June 12 summit in Singapore between North Korean leader Kim Jong Un and US President Donald Trump.

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A report published recently by NBC News, citing unnamed US officials, said 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 talks with the United States."

Another US official was quoted saying there is "absolutely unequivocal evidence" that North Korea was trying to "deceive" the US.

"The intelligence community assessment that North Korea is taking steps to deceive the United States would be consistent with regime behavior during all previous diplomatic negotiations," Bruce Klinger, a former CIA division chief for Korea and senior research fellow for Northeast Asia at the Heritage Foundation in Washington, told DW.

However, Klinger emphasized that expanding production of fissile material did not violate the US-North Korea joint declaration signed in Singapore. "No real denuclearization agreement has yet been reached," he said.

"As the US seeks to put meat on the meager bones of the Singapore Communique, it needs to emulate the lengthy, detailed treaty text and robust verification regimes of arms control treaties with the Soviet Union rather than the flawed North Korean agreements of the past," added Klinger.

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'Very clear' expectations from Washington

US Secretary of State Mike Pompeo is heading to North Korea on Thursday for the first round of talks following the June summit. According to a US State Department press briefing, the visit will center on "consultations with the North Korean government" about what Trump and Kim "agreed to" in Singapore.

State Department Spokeswoman Heather Nauert said that North Korea was "very clear" in terms of US expectations and Secretary Pompeo would be "very blunt" in what he "expects from the North Koreans."

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Pompeo tweeted before the Singapore summit that the US remained "committed to the complete, verifiable, irreversible denuclearization of the Korean Peninsula." This is commonly referred to as "CIVD."

After the summit on June 13, he told reporters in Seoul, "I hope we'll see — you used the term 'major disarmament' — yes, we're hopeful that we can achieve that in the next two and a half years."

"Secretary of State Pompeo will need to get Pyongyang to publicly and unambiguously embrace the CVID concept and accept extensive inspections if the Trump administration is going to achieve real denuclearization," said analyst Klinger.

'Complete denuclearization?'

President Trump's statements since the Singapore summit indicate the administration wants to capitalize on the political significance of the meeting. While dialogue itself is a breakthrough, there has yet to be any indication that North Korea is diminishing its weapons program, despite concessions from the US.

Directly after the summit, Trump tweeted that "there is no longer a nuclear threat from North Korea." Yesterday, the US leader declared, "If not for me, we would be at war with North Korea."

Despite Trump's assertions, a recent report released by 38 North, a North Korea research and analysis website run by the Stimson Center think tank in Washington, concluded that Pyongyang was carrying out upgrades to North Korea's Yongbyon Nuclear Scientific Research Center.

The report said that "commercial satellite imagery from June 21" indicated "improvements to the infrastructure" at Yongbyon were "continuing at a rapid pace." This included the completion of a cooling system for the plutonium production reactor.

Slowing down production?

Jenny Town, managing editor at 38 North, told DW that it would be incorrect to assume that Pyongyang would slow down its weapons production capability ahead of any agreements with the US. The pace of North Korea's scaling down of weapons production would depend on the content and outcome of negotiations, all of which remain uncertain.

"The only definitive take away from the imagery is that work, which had started at these sites prior to the summit, did not stop immediately. It would have been actually quite surprising if it had," said Town, adding that new unpublished imagery acquired on Tuesday by 38 North appears to show that work at the site had slowed.

"We would expect that trend to continue and no new projects to be started," she said, adding that work at the major facilities should "begin to slow or stop as negotiations progress."

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"However, until the agreement is settled, I would expect that some level of activity at these sites, even if it's just for maintenance, is likely to continue."

Another image analysis released on July 2, by the Middlebury Institute of International Studies, shows that North Korea is expanding an important missile production site at the Chemical Material Institute in Hamhung. According to the report, the facility produces essential parts for solid-fueled missiles, including the Pukgugsong series.

Unrealistic timelines from the US

On Sunday, President Trump's National Security Advisor John Bolton told CBS that the US could "move very quickly" and that Secretary Pompeo would discuss with the North Koreans "how to dismantle all of their weapons of mass destruction and ballistic missile programs in a year."

Experts say this assessment vastly underestimates the state of North Korea's capability.

"North Korea's nuclear program and program infrastructure is quite extensive with many unknowns," said Town, adding that technical experts with deep knowledge of North Korea's nuclear program give estimates of between five and 10 years to "engineer complete, verifiable dismantling of the nuclear and ballistic missile infrastructure."

Read more: SIPRI: Nuclear weapons are still being developed

"Politically, there is no trust between the US and North Korea. Pyongyang would therefore be reluctant to dismantle its core nuclear capabilities and become vulnerable to US (and South Korean) policy shifts in the future, especially as administrations change," she said.

"Despite Trump's claim that 'there is no longer a nuclear threat from North Korea,' there has been no diminution in Pyongyang's arsenal or programs," said Klinger.

"The regime continues to have an estimated arsenal of more than 30 nuclear weapons, missiles that can already threaten South Korea and Japan with nuclear weapons and, according to then-CIA Director and current Secretary of State Mike Pompeo, is only a 'handful of months' away from having the ability to target the entire United States with nuclear weapons," he added. 

"President Trump's claim that the North Korea nuclear problem is solved is premature to say the least."