President Trump is still hoping he can meet with Kim Jong Un and convince him to give up his nukes. But new satellite imagery of North Korea’s nuclear test site suggests that the North’s may not be game for the “complete, verifiable and irreversible” dismantling of their nuclear program Washington has called for.

North Korea destroyed its Punggye-ri nuclear test site on Friday in front of an audience of reporters after unilaterally offering to destroy the site in mid-May. North Korean state media hailed the move as “an important process for global nuclear disarmament” carried out with “high-level transparency,” and President Trump praised it as “a very smart and gracious gesture.” But some experts suspect the site may have been sanitized by the North Koreans before reporters arrived.

Well before the dismantlement ceremony, satellite imagery of the south entrance obtained by the Middlebury Institute for International Studies show activity at the site as the North began to remove guard structures. The photo shows a heavy truck at the entrance to the south tunnel at the site.

The imagery was captured on May 7, a day before Secretary of State Mike Pompeo visited North Korea for a second time and five days before North Korean officials officially announced a schedule for the destruction of the site. Video of the south tunnel entrance recorded by Sky News’ Tom Cheshire on the day the test site was dismantled also shows parts of the tunnel’s walls carved out where cables carrying data from the test chamber would be. As early as May 2, U.S. intelligence officials told CBS News that the North had begun to remove cables from the site.

It’s not clear what, if anything, the truck seen at the tunnel entrance was carrying but Jeffrey Lewis, director of Middlebury’s East Asia Nonproliferation Program, suspects that the activity shown in satellite imagery depicted the North removing material from the test site.

“The only reason to sanitize the site is if you are planning on protecting national security information,” Lewis told The Daily Beast. “The North Koreans are still treating information about their nuclear weapons program as sensitive—that suggests North Korea is unlikely to hand over actual nuclear weapons.”

On Friday, the White House National Security Council’s top East Asia staffer Matthew Pottinger told surrogates in an off-the-record briefing that was independently described to The Daily Beast that “What you didn't know is that Secretary Pompeo and the South Korean government were both promised that experts would be invited to verify today's demolition and to do some advance work there.”

Pottinger referred to the North’s failure to make good on the apparent offer he described as a broken promise, concluding that “we will not have forensic evidence that much was accomplished.”

On May 15, shortly after North Korea announced a schedule for the dismantling of Punggye-ri, State Department spokeswoman Heather Nauert told reporters: “Hopefully we’ll be in the position to be able to do that, but again, I don’t want to get ahead of that process.”

The soil, equipment, and even the air around nuclear test sites can yield valuable information about the weapons detonated within them. Instrumentation at a test site can offer insights into how advanced a nuclear program is. Following previous North Korean nuclear tests, the U.S. Air Force flew WC-135 Constant Phoenix aircraft—planes equipped with sensors to collect atmospheric samples and garner clues about the fuel used in a nuclear detonation—outside of North Korean airspace.

Having access to a test site itself could provide even more information about the North’s nuclear weapons but the U.S. didn’t get the chance—the North never invited American officials or technical experts to Punggye-ri. Tom Cheshire of Sky News wrote that North Korean officials even confiscated a radiation dosimeter he brought with him to the country in order to monitor potentially unsafe levels of radiation exposure.

Pompeo welcomed the offer to destroy Punggye-ri as “good news” and “one step along the way” when North Korea first announced it. But sanitization of the Punggye-ri test site falls far short of Pompeo’s high bar for of "complete, verifiable, irreversible denuclearization,” and puts into doubt the North’s willingness to accept the kinds of verification measures often included in arms-control agreements.

North Korea had carried out half a dozen nuclear tests at its Punggye-ri site with the first test taking place in 2006. It carried out a final test in September 2017 of what many believe was a thermonuclear weapon. In late April, months after the successful demonstration of a North Korean intercontinental ballistic missile, Kim Jong Un announced that “We no longer need any nuclear tests” and that Punggye-ri has "completed its mission."