According to a “diplomatic source” quoted by South Korean media, the United States knows where one of North Korea’s two uranium enrichment facilities is located and expects dictator Kim Jong-un to reveal the existence of both facilities to the world and invite international inspections.

According to a report by Korea Joongang Daily, the diplomatic source said Kim has “made up his mind to reveal such facilities as one of the big actions he plans to take” during his June 12 meeting with U.S. President Donald Trump in Singapore.

The report suggests the two secret facilities in question are separate from the widely-known reactor at Yongbyon, and there might be more than two of them:

American nuclear weapons expert Siegfried Hecker, a professor emeritus at Stanford University, led a group of U.S. scientists to North Korea’s Yongbyon nuclear complex in November 2010. He later said that one facility contained 2,000 centrifuges producing low-enriched uranium but that the facility could be easily be converted to produce HEU bomb fuel — and that parallel facilities could exist elsewhere. They were the last group of U.S. scientists to make such a visit, and since then, North Korea’s HEU facilities and stockpile have been opaque. “The United States views that besides the one or two secret facilities, there can be more secret HEU facilities in North Korea and it is in the process of confirming them,” said this source. Another official indicated the exact location of such secret uranium enrichment facilities is a closely guarded secret and not confirmed, but there is a high likelihood of one being located underground near the Panghyon Airfield in Kusong, a city in North Pyongan Province, or in some other location in the province.

Another “diplomatic source in Washington” told Korea Joongang Daily that Treasury Secretary Steven Mnuchin will not accompany President Trump to Singapore, sending a signal to North Korea that it will be rewarded with phased relief from sanctions with each step toward denuclearization it takes. The denuclearization process would likely take several years to complete, so U.S. negotiators and inspectors will have to remain on guard for the kind of delaying tactics North Korea has often used in the past.

One of the sources for the Korean report intriguingly suggested the U.S. is not revealing exactly what it wants out of North Korea, including the structure of the international inspection regime that would verify denuclearization, because it does not want Kim to steal the spotlight at the summit by making a “big proposal” right up front.

Prior to the “diplomatic thaw” at the beginning of 2018, North Korea dramatically ramped up uranium enrichment and doubled the size of the facility at Yongbyon, giving it the capacity to produce up to six nuclear bombs per year.

National Security Adviser John Bolton suggested on Sunday that North Korea’s nuclear weapons be dismantled and sent to the U.S. Department of Energy research facility in Oak Ridge, Tennessee.

Bolton said denuclearization means “getting rid of the uranium enrichment and plutonium processing capabilities, it means addressing the ballistic missile issue, a lot of things like that.”