Trump denies paying North Korea $2 million for Otto Warmbier's medical care

President Donald Trump denied that the U.S. paid North Korea $2 million for Otto Warmbier's medical care after reports emerged Thursday that the regime forced U.S. officials to sign a pledge to do so.

"No money was paid to North Korea for Otto Warmbier, not two Million Dollars, not anything else," the president tweeted.

White House national security adviser John Bolton in a Fox News Sunday interview this weekend, reiterated the administration's position that the U.S. did not pay North Korea $2 million for Warmbier's medical care, despite a document pledging to make that payment.

Warmbier, an American college student detained by North Korea for allegedly stealing a propaganda poster, died six days after he was freed by North Korea and handed over to U.S. officials in June 2017.

The White House had declined to comment Thursday, telling ABC News, "We do not comment on hostage negotiations, which is why they have been so successful during this administration."

The Washington Post first reported that the U.S. officials who arrived in June 2017 to bring Warmbier back to the U.S. were presented with a bill of $2 million for Warmbier's medical expenses. On Trump's orders they signed it, according to the report.

A U.S. official told ABC News a bill was given to the American team, but could not say whether any money was ever paid.

A senior U.S. administration official confirmed the existence of the bill but told ABC News, “It didn’t matter, we were not going to pay it.”

A lawyer for the Warmbier family said he was unaware of the demand by North Korea and declined to comment further.

Warmbier was on a tour group in January 2016 when he was arrested at Pyongyang Sunan International Airport and sentenced a few weeks later to 15 years of hard labor during a second emotional court appearance, saying, "I have made the worst mistake of my life." Shortly after that, he became ill and fell into a coma, although it's unclear why or for how long.

Doctors who examined Warmbier later said he had suffered from injuries related to cardiopulmonary arrest and was in a state of unresponsive wakefulness, characterized by a lack of awareness of one’s environment and self despite being awake. Scans of his brain showed extensive loss of tissue in all regions of his brain, but they found no evidence of botulism -- what North Korea had blamed his condition on.

In May 2017, North Korean officials notified the U.S. that they wanted to meet urgently to discuss his case. The top U.S. diplomat for North Korea, Joseph Yun, met with North Korea's delegation to the United Nations in New York in June and was told about Warmbier's dire medical condition for the first time.

After consulting Trump, then Secretary of State Rex Tillerson instructed Yun to prepare to travel to North Korea to bring Warmbier back to the U.S. Sometime during that week, the U.S. government also notified Warmbier’s family of his condition.

On June 13, Warmbier was evacuated from North Korea by Yun and a medical team, later arriving Cincinnati. Six days later Warmbier died in a hospital.

The Warmbier family has sued the Kim regime for their son's wrongful death, winning a $500 million judgment in December. It's unlikely North Korea will ever pay that money, but the family said it was "thankful that the United States has a fair and open judicial system so that the world can see that the Kim regime is legally and morally responsible for Otto’s death."

Two months later, however, after his second meeting with Kim Jong Un, Trump seemed to absolve the North Korean dictator of Warmbier's death.

"I don't believe that he would have allowed that to happen," Trump said of Kim during a post-summit news conference. "He felt badly about it ... he knew the case very well, but he knew it later."

Trump later tweeted that he was "misinterpreted ... Of course I hold North Korea responsible... for Otto's mistreatment and death."

But he didn't mention Kim by name -- something Secretary of State Mike Pompeo has declined to do as well.

Several U.S. hostages have been freed under the Trump administration, including Pastor Andrew Brunson from Turkey, human rights worker Aya Hijazi from Egypt and three other U.S. citizens held by North Korea -- Kim Dong Chul, Tony Kim and Kim Hak Song.

"'President Donald J. Trump is the greatest hostage negotiator that I know of in the history of the United States'," Trump tweeted Friday, quoting an unnamed "Cheif [sic] Hostage Negotiator, USA!"

He also took a shot at the Obama administration, accusing it of paying for the release of U.S. hostages from Iran. Four Americans were released by Iran and the U.S. paid $400 million to Iran as part of a settlement the U.S. owed the Iranian government. Several days later, the U.S. sent another payment of $1.3 billion -- the amount of interest owed. The cash payments were controversial even within the Obama administration. Government officials, however, argued that it was not a hostage payment but money the U.S. owed Iran from before the 1979 revolution.

ABC News' Katherine Faulders and Jonathan Karl contributed to this report.