Washington(CNN) New satellite imagery obtained by CNN reveals North Korea has recently taken steps to conceal a facility US intelligence agencies believe is being used to store nuclear weapons, a move that could add to the growing sense of urgency from critics who argue the Biden administration needs to articulate a clear strategy on how it will deal with Kim Jong Un going forward.
The image, captured by Maxar on February 11 and analyzed by experts at the Middlebury Institute, shows North Korea built new structures at its Yongdoktong site over the course of 2020 -- an effort researchers say is likely intended to obscure a pair of underground tunnel entrances that lead to the facility where nuclear weapons are stored.
"Images released by Maxar show the pair of tunnel entrances as late as December 2019 and a new building-like structure visible by February 2021," according to Jeffrey Lewis, a professor at the Middlebury Institute of International Studies, which specializes in open-source intelligence.
Yongdoktong has been previously identified by US intelligence as a suspected North Korean nuclear weapons storage facility and is still believed to be used for that purpose, a US intelligence official told CNN.
The satellite images obtained by CNN reaffirm what has been widely known among US national security officials and experts for years: North Korea continues to actively develop nuclear weapons at sites around the country while taking further steps toward hiding the stockpile it has already accumulated.
Recent construction at the site will certainly catch the attention of US intelligence agencies as they carefully monitor sites suspected to be part of Pyongyang's nuclear weapons program, according to two former intelligence officials and congressional lawmakers.
Lawmakers and key US allies are eagerly awaiting details about President Joe Biden's North Korea policy, which they expect will be announced publicly in the coming weeks when the administration has completed a policy review, according to multiple sources familiar with the internal discussions.
The clear evidence North Korea's nuclear program is continuing adds to the urgency of the situation, with critics arguing that a policy review that goes on for too long risks developments occurring that will further complicate achieving the administration's goal of denuclearization.
"No matter how comical the effort, North Korea continues to upgrade its nuclear weapons facilities and makes efforts to conceal them," Lewis said, referring to the fact that US intelligence agencies have been watching the site for years.
The Office of the Director of National Intelligence and the Pentagon, citing intelligence matters, declined to comment. The State Department did not respond to CNN's request for comment on the new imagery.
Beyond stressing a commitment to work alongside regional allies, the Biden administration has said little about its plans for engaging with North Korea during its first weeks in office, with top officials only offering vague statements reaffirming the US commitment to "denuclearization" but offering few specifics.
"The President's view is --- without question that North Korea's nuclear ballistic missile and other proliferation related activities constitutes serious threat to the international peace and security of the world and undermine the global non-proliferation regime," said White House spokesperson Jen Psaki last month.
Rep. Andy Kim and other former US officials told CNN that they hope the Biden administration moves quickly to engage with North Korea before they conduct another missile test or take other provocative steps later this year that may make diplomacy more difficult.
"I think there's an opportunity for us to really push on a number of fronts ... and not just have everything live or die based off of denuclearization. I think that if we go down that route again, we will be hit with the same problems that we've had time and time again. I do hope the Biden team takes a different tack this point," Kim, a Democratic member of the House Foreign Affairs and Armed Services committees, told CNN in a recent interview.
Rep. Adam Kinzinger, a Republican member of the House Foreign Affairs Committee, said he still believes the Biden administration should continue to work towards a "nuclear-free North Korea" but acknowledged there are no easy answers as far as how to pursue that goal.
"Deposing Kim Jong Un is not realistic right now and it shouldn't be our state of policy. Korean reunification is probably not very realistic, so how do we prevent a nuclear war from breaking out or North Korea from using their supposed of nuclear capability as a way for leverage," he told CNN.
The timing of the movements at Yongdoktong is noteworthy but requires some examination because North Korea's actions can never be taken at face value, said a former senior US intelligence official. If North Korea is seeking to speed up engagement with the Biden administration and does not want to use a provocation like a missile test this move could be undertaken to catch the attention of the US.
Former intelligence officials say recent efforts to obscure the view of American spy satellites could be intended to remind the Biden administration that work on these programs continues even as the White House deliberates on a diplomatic path forward.
North Korea's tactic to try to use "deception and denial" is not something new, one former official explained. North Koreans are known to use the tactic to draw US attention to a matter, allow miscalculation, and deny that they are doing it.
While the details of Biden's plan for North Korea are being developed by the administration, the White House is not counting out the possibility of direct engagement down the line.
Trump broke the mold when it comes to broaching the intractable challenge of North Korea. Instead of working in lockstep with US allies in the region, he prioritized developing a personal bond with Kim Jong Un. The leaders exchanged frequent letters and met in person three times. Yet, despite this unprecedented engagement, North Korea is more dangerous today than it was when Trump took office.
As Biden's national security team begins to develop their North Korea policy, they will face the challenge of shaping a nuanced approach that rejuvenates a commitment to allies, avoids simply reverting back to the pre-Trump North Korea strategy characterized as "strategic patience" during the Obama administration, and can produce results on the ultimate goal of denuclearization.
Secretary of State Tony Blinken said the administration will both consider how to increase pressure on Pyongyang and how to draw them in with diplomacy, adding that nothing can be done without consulting with allies.
"We intend to review the entire approach in policy toward North Korea, because this is a hard problem that has plagued administration after administration after administration and it's a problem that has not gotten better. In fact, it's gotten worst," Blinken said during his confirmation hearing. He added that they will look at options "that can be effective in terms of increasing pressure on North Korea to come to the negotiating table as well as what other diplomatic initiatives may be possible."
Anthony Ruggiero, who previously served as the National Security Council Director for North Korea during the Trump administration, also said he believes the Biden administration can use sanctions as leverage for negotiations.
"Sanctions need to be at a level where it can provide leverage for negotiations. The sanctions toward the end of the Trump administration on North Korea were sporadic at best, and in some cases non-existent, so they do need to spend some time rebuilding some more of the pressure to allow productive negotiations," according to Ruggiero, who is currently a senior fellow at the Washington-based think-tank Foundation for Defense of Democracies.
The Biden administration is also expected to begin publicly speaking out against any future North Korean provocations unlike the approach in the latter part of the Trump administration, current and former administration officials tell CNN.
Provocations from North Korea, which traditionally mark the beginning of every administration, could be delayed due to the pandemic, former US officials told incoming Biden officials during transition meetings. They believe that the pandemic has put North Korea in a delicate position where it cannot afford further sanctions and cannot engage in diplomacy.
But Kim Jong Un hates being out of the spotlight and it is likely that he will want to test the incoming team, making it virtually impossible to predict how the despot will act in the early days of Biden presidency.
Some North Korea experts believe that the Biden administration should send a direct signal to North Korea to demonstrate willingness to engage, sooner rather than later.
"It is a moment of opportunity," said Gen. Vincent Brooks, a retired US Army general who commanded United States Forces Korea during the Trump administration. "I hope they will seek communication early on. It may begin through backchannels first but there must be a conduit of communication directly to Kim Jong Un."