Returning from meeting Kim Jong Un in Singapore earlier this month, U.S. President Donald Trump assured the nation they could “sleep well tonight” because “there is no longer a nuclear threat from North Korea.”

Fresh evidence suggests Trump was wrong and that despite pledges to work toward denuclearization, the government in Pyongyang has continued to improve its nuclear enrichment facilities.

According to commercial satellite imagery from June 21, obtained and analyzed by 38 North, “improvements to the infrastructure at Yongbyon Nuclear Scientific Research Center are continuing at a rapid pace.”

The images show that modifications to the cooling system of the plutonium production reactor appear complete, though the analysts could not give a clear indication of whether the reactor was operational.

“The increased roof staining at the northwest corner of the cascade halls indicates continued operations at the Uranium Enrichment Plant,” the report adds.

Though the development work at Yongbyon could be interpreted as a slap in the face to the Trump administration, 38 North said the work “should not be seen as having any relationship to North Korea’s pledge to denuclearize. The North’s nuclear cadre can be expected to proceed with business as usual until specific orders are issued from Pyongyang.”

In Singapore, Trump and Kim signed a declaration pledging to work toward the complete denuclearization of the Korean Peninsula. But critics have blasted the lack of detail in the document, specifically how and when denuclearization will happen.

U.S. Secretary of State Mike Pompeo refused Monday to put a timeline on negotiations for denuclearization, despite a senior defense official earlier claiming that Washington was about to present Pyongyang with a timeline and “specific asks.”

Kim last month invited foreign journalists to North Korea to witness the destruction of the country’s only known nuclear test site at Punggye-ri — a show of goodwill ahead of the summit.

Jenny Town, an analyst at 38 North, said on Twitter that the infrastructure improvements at Yongbyon “underscores reason why an actual deal is necessary, not just a statement of lofty goals.”