The announcement on Warmbier's release came as former National Basketball Association player Dennis Rodman was paying a return visit to Pyongyang. The official spoke to the AP on condition of anonymity because no formal statement had been released.
Instead, the administration credited the release to its diplomatic intervention. It is common for sections of tourist hotels to be reserved for North Korean staff and off-limits to foreigners.
The announcement came amid tension between Washington and Pyongyang following a series of missile tests by the North, focusing attention on an arms buildup that Pentagon chief Jim Mattis on Monday dubbed "a clear and present danger to all".
Such direct consultations between the two governments are rare.
And North Korea is clearly at the top of the agenda for many in the administration. Immediately after that visit, North Korea contacted the U.S.to request a meeting with a State Department official. One month later, he was sentenced to prison.
The three other detainees are all Korean-American men.
The parents of the 22-year old American college student freed by North Korea say he is in a coma.
In March 2016, Warmbier, who stopped in North Korea on a New Year's Eve tour in 2015 en route to a year of studies in Hong Kong, was convicted of committing "hostile acts against the state" and sentenced to 15 years in prison.
The State Department, at the direction of President Trump, put out a statement saying they had secured the release of Warmbier.
"He is being medivacked to the United States", the Warmbier family told CNN in a statement. Kim is one of three USA citizens being held by Kim Jon Un's regime.
Warmbier's parents were told their son was given a sleeping pill soon after his trial in March past year and never woke.
Melania Trump, son Barron move into the White House
His daughter and top adviser, Ivanka Trump, is leading events focused on workforce development and college affordability. He had told lawmakers at his January confirmation hearing that he had not met with Russians during the campaign.
"We want the world to know how we and our son have been brutalized and terrorized by the pariah regime" in North Korea, Warmbier's parents said. "We are so grateful that he will finally be with people who love him." they added. The official referred to them as "hostages".
"In no uncertain terms, North Korea must explain the causes of his coma". Pyongyang accused Kim of receiving a USB drive and documents containing some North Korea nuclear secrets.
Following the May meeting in Oslo, North Korea urgently requested another meeting, which took place last week between the US envoy on North Korea, Joseph Yun, and the North's ambassador at the U.N.in NY. Warmbier's family said in a statement that he is in a coma and on his way home.
Rodman isn't representing the U.S. government or serving as President Donald Trump's emissary, Anton said. He was medically evacuated from the country early this week and is expected to return home to Cincinnati on Tuesday.
On Monday, during the administration's first cabinet meeting - a weird, North Korean-style pageant of loyalty pledges and recitations of praise for the leader - Tillerson laid down a marker for friend and foe alike.
Rodman was a cast member on two seasons of Trump's "Celebrity Apprentice".
North Korean officials told Mr Warmbier's family he fell ill from botulism after his trial then went into a coma after taking a sleeping pill. "My goal is to go over there and try to see if I can keep bringing sports to North Korea".
Warmbier isn't the only American held there; there are three others.
The North has occasionally jailed U.S. citizens and released them only after visits by high-profile political figures, including former president Bill Clinton. North Korea, however is known for forcing prisoner's confessions.
PUST and Yanbian University of Science and Technology are sister schools. He had also taught at the university. At a government-organized news conference, he apologized for trying to steal military secrets in collusion with South Koreans.
The parents were also quoted as saying that North Korean officials informed them via US envoys that Warmbier fell ill from botulism sometime after his trial in March previous year and fell into a coma after taking a sleeping pill.