The U.S. received a $2 million hospital bill from the North Korean government for the care of American Otto Warmbier, who fell into a coma for unknown reasons while he was imprisoned in the country before he died in the U.S. in 2017, Fox News has confirmed.

Pyongyang authorities insisted the U.S. envoy sent to retrieve the University of Virginia student sign a pledge to pay the bill before allowing Warmbier’s comatose body to return to the United States, the Washington Post reported Thursday. Sources familiar with the matter confirmed the bill and the amount to Fox News.

Citing two people familiar with the situation, the Post reported the envoy signed an agreement to pay the medical bill on instructions from President Trump. However, a source told Fox News the U.S. did not pay money to North Korea.

KIM JONG UN’S TOP ADVISER, NORTH KOREA’S KEY NUCLEAR NEGOTIATOR WITH US, REMOVED FROM POST

The White House declined to comment, with Press Secretary Sarah Sanders saying in a statement: “We do not comment on hostage negotiations, which is why they have been so successful during this administration.”

Warmbier was on tour in North Korea when he allegedly stole a propaganda sign from a hotel. He was arrested in January 2016 and sentenced to 15 years in prison with hard labor in March 2016.

The Ohio native, then 21, fell into a coma for unknown reasons while in custody and was held in that condition for another 17 months. North Korean officials did not tell American officials until June 2017 that he had been unconscious the entire time. He died less than a week after he returned to the U.S. the same month.

North Korea repeatedly has denied accusations Warmbier was tortured and officials told their U.S. counterparts at the time that he had suffered from botulism and then slipped into a coma after taking a sleeping pill.

PUTIN BUILDS HIS 'AUTHORITARIAN AXIS': KIM JONG UN SUMMIT THE LATEST MOVE DESIGNED TO DAMAGE US POWER ABROAD

News of his condition sparked an effort by Joseph Yun, the State Department’s point person on North Korea at the time, to get Warmbier home, the Post reported.

Yun and an emergency medicine doctor, Michael Flueckiger, traveled to the North Korean capital on a medical evacuation plane and were taken to the Friendship Hospital. There, they found Warmbier lying in a room marked “intensive care unit” and had a feeding tube in his nose.

The Post reported Yun was asked to sign the pledge for payment when he went to retrieve Warmbier. He reportedly called then-Secretary of State Rex Tillerson, who called the president.

Both Tillerson and Trump instructed Yin to sign the pledge, sources told the Post.

NORTH KOREA MUST PAY $501 MILLION TO OTTO WARMBIER’S PARENTS, JUDGE RULES

Sources told Fox News that Flueckiger signed a medical form for Warmbier's release, but that this was the first time they had heard about a hospital bill.

A State Department spokesman declined to comment to Fox News and referred to the statement by the White House. Yun, who retired in early 2018, declined to comment to the Post.

Yun told CNN on Thursday that while he could neither discuss specifics of negotiations nor confirm the Post's report, it was his understanding that in previous prisoner releases, it's been standard for there to be some exchange of money for hospital costs. He said his orders were to "completely do whatever you can to get Otto back."

"It is my understanding that in previous instances that there was some exchange of money which was justified on the basis of hospital costs, so I know that in previous prisoner releases there was money handed over," he said, adding that he understood the orders to be directly from the president.

Warmbier’s father, Fred Warmbier, told the news outlet he wasn’t aware of the medical bill and said it sounded “random.”

Fred and Cindy Warmbier sued North Korea over their son’s death and in December were awarded $501 million in damages – money that the Hermit Kingdom will probably never pay.

While the Warmbiers blamed North Korean leader Kim Jong Un, President Trump has said he believes Kim’s claims that he did not know about the student’s treatment.

CLICK HERE TO GET THE FOX NEWS APP

Trump and Kim have met in two separate summits. The most recent, held in February, ended without an agreement on denuclearization of the Korean Peninsula.

Sen. Rob Portman, R-Ohio, told Fox News: “Otto Warmbier was mistreated by North Korea in so many ways, including his wrongful conviction and harsh sentence, and the fact that for 16 months they refused to tell his family or our country about his dire condition they caused. No, the United States owes them nothing. They owe the Warmbier family everything.”

Fox News' Rich Edson, John Roberts, Keller Chernenkoff, Blake Burman, Nicholas Kalman and Mike Emanuel contributed to this report.