CINCINNATI (AP) - An American college student whose parents say has been in a coma while serving a 15-year prison term in North Korea was released and returned to the United States Tuesday as the Trump administration revealed a rare exchange with the reclusive country.

An airplane carrying Otto Warmbier, who's from Ohio, arrived in Cincinnati shortly before 10:20 p.m. Warmbier was then taken by ambulance to the University of Cincinnati Medical Center for treatment.

His release came during a visit to North Korea by former NBA star Dennis Rodman, one of few people to have met both North Korean leader Kim Jong Un and President Donald Trump.

Otto Warmbier, a 22-year-old college student detained and imprisoned in North Korea, is carried off of an airplane at Lunken Airport in Cincinnati on Tuesday, June 13, 2017. Warmbier arrived in Ohio after being released by North Korea, where he was serving a 15-year prison term with hard labor for alleged anti-state acts. His parents have said he has been in a coma and was medically evacuated. (Sam Greene/The Cincinnati Enquirer via AP)

Department of State spokeswoman Heather Nauert told reporters Rodman had nothing to do with Warmbier's release. Rodman had told reporters before arriving in Pyongyang that the issue of Americans detained by North Korea is "not my purpose right now."

Securing Warmbier's release "was a big priority" for President Donald Trump, who worked "very hard and very closely" with Secretary of State Rex Tillerson, spokeswoman Sarah Huckabee Sanders said.

While North Korea's move to free Warmbier could potentially provide an opening for talks on security issues, the prospects still appear bleak. International negotiations on the dispute over North Korea's nuclear program have been in limbo for years, as the U.S. cranks up economic sanctions and North Korea won't give up weapons it considers a guarantee against invasion.

The detention of Americans, often sentenced to draconian prison sentences for seemingly small offenses in the totalitarian nation, has compounded tensions between Washington and Pyongyang. Three Americans remain in custody.

Warmbier, a 22-year-old University of Virginia undergraduate, was convicted and sentenced in a one-hour trial in North Korea's Supreme Court in March 2016. He was sentenced to 15 years in prison with hard labor for subversion after he tearfully confessed that he had tried to steal a propaganda banner.

Tillerson announced that the Department of State had secured Warmbier's release at the direction of the Republican president. He said Warmbier, of Wyoming, in suburban Cincinnati, was en route to the U.S.

Warmbier's parents, Fred and Cindy Warmbier, said he was in a coma and was flying home. They said they were told he has been in a coma since his trial, when he was last seen in public, and they had learned of this only one week ago.

"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."

In Wyoming, resident Amy Mayer said news of his release had sent waves of shock and joy through the neighborhood.

A White House official said Trump had instructed Tillerson to take all appropriate measures to secure the release of Americans held in North Korea. The official referred to them as "hostages."

The U.S. government accuses North Korea of using such detainees as political pawns. North Korea accuses Washington and South Korea of sending spies to overthrow its government.

It's unclear if Warmbier's release during Rodman's visit was purely coincidental. Rodman has traveled to the isolated nation four times since 2013, attracting a lot of publicity, much of it unfavorable. In 2014, Rodman arranged a basketball game with other former NBA players and North Koreans and regaled leader Kim with a rendition of "Happy Birthday."

Rodman's current trip is his first since Trump, his former "Celebrity Apprentice" boss, became president. He told reporters in Beijing, as he departed for Pyongyang, that he hopes his trip will "open a door" for Trump.

North Korea poses one of the greatest national security challenges for Trump as it tries to develop a nuclear-tipped missile that could strike America. He is looking to increase economic and diplomatic pressure on North Korea, with help from China but has said he's open to meeting Kim.

In the past, North Korea has held out until senior U.S. officials or statesmen came to personally bail out detainees. A 2009 visit by former President Bill Clinton, a Democrat, secured the freedom of American journalists Euna Lee and Laura Ling.

Tillerson said the Department of State was continuing "to have discussions" with North Korea about the release of other three American citizens imprisoned there. They are:

- Kim Hak Song, who was detained in early May to be investigated for committing unspecified hostile acts, North Korea has said. He worked at the Pyongyang University of Science and Technology.

- Tony Kim, who also goes by his Korean name Kim Sang-duk, was detained April 22 at the Pyongyang airport. He had also taught at the university. He was accused of committing unspecified criminal acts intended to overthrow the government.

- South Korean-born U.S. citizen Kim Dong Chul, who was sentenced in April 2016 to 10 years in prison with hard labor after being convicted of espionage.

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AP reporters Josh Lederman and Ken Thomas in Washington, Eric Talmadge in Pyongyang, North Korea, Daniel Sewell in Cincinnati and video journalist Sara Gillesby in New York contributed to this report.

A crying woman exits a transport plane carrying Otto Warmbier, a 22-year-old University of Virginia undergraduate student who was imprisoned in North Korea in March 2016, as he is transferred from his transport aircraft to an ambulance at Lunken regional airport, Tuesday, June 13, 2017, in Cincinnati. Warmbier, serving a 15-year prison term for alleged anti-state acts, was released and medically evacuated from the reclusive country Tuesday and has been in a coma for months, his parents said. (AP Photo/John Minchillo)

Two people hug outside the plane carrying Otto Warmbier, a 22-year-old University of Virginia undergraduate student who was imprisoned in North Korea in March 2016, before he is transferred from a transport aircraft to an ambulance at Lunken regional airport, Tuesday, June 13, 2017, in Cincinnati. Warmbier, serving a 15-year prison term for alleged anti-state acts, was released and medically evacuated from the reclusive country Tuesday and has been in a coma for months, his parents said. (AP Photo/John Minchillo)

The legs of Otto Warmbier, a 22-year-old University of Virginia undergraduate student who was imprisoned in North Korea in March 2016, are seen as medical personnel transfer him from a transport aircraft to an ambulance at Lunken regional airport, Tuesday, June 13, 2017, in Cincinnati. Warmbier, serving a 15-year prison term for alleged anti-state acts, was released and medically evacuated from the reclusive country Tuesday and has been in a coma for months, his parents said. (AP Photo/John Minchillo)

Medical personnel and visitors gather at the nose of a transport plane carrying Otto Warmbier, a 22-year-old University of Virginia undergraduate student who was imprisoned in North Korea in March 2016, before he is transferred to an ambulance at Lunken regional airport, Tuesday, June 13, 2017, in Cincinnati. Warmbier, serving a 15-year prison term for alleged anti-state acts, was released and medically evacuated from the reclusive country Tuesday and has been in a coma for months, his parents said. (AP Photo/John Minchillo)

Otto Warmbier, center on a stretcher, a 22-year-old college student detained and imprisoned in North Korea, is loaded into an ambulance after being carried off of an airplane at Lunken Airport in Cincinnati on Tuesday, June 13, 2017. Warmbier arrived in Ohio after being released by North Korea, where he was serving a 15-year prison term with hard labor for alleged anti-state acts. His parents have said he has been in a coma and was medically evacuated. (Sam Greene/The Cincinnati Enquirer via AP)

FILE - In this Feb. 29, 2016 file photo, American student Otto Warmbier speaks to reporters in Pyongyang, North Korea. Secretary of State Tillerson said Tuesday, June 13, 2017, that North Korea released the jailed U.S. university student (AP Photo/Kim Kwang Hyon, File)

FILE - In this March 16, 2016, file photo, American student Otto Warmbier, center, is escorted at the Supreme Court in Pyongyang, North Korea. Warmbier, whose parents say has been in a coma while serving a 15-year prison term in North Korea, was released and returned to the United States Tuesday, June 13, 2017, as the Trump administration revealed a rare exchange with the reclusive country. (AP Photo/Jon Chol Jin, File)

FILE - In this March 16, 2016, file photo, American student Otto Warmbier, center, is escorted at the Supreme Court in Pyongyang, North Korea. Warmbier, whose parents say has been in a coma while serving a 15-year prison term in North Korea, was released and returned to the United States Tuesday, June 13, 2017, as the Trump administration revealed a rare exchange with the reclusive country. (AP Photo/Jon Chol Jin, File)

Denise Koesterman ties blue-and-white awareness ribbons along Springfield Pike near the family home of Otto Warmbier, a 22-year-old University of Virginia undergraduate student who was imprisoned in North Korea in March 2016, in the Wyoming suburb of Cincinnati on Tuesday, June 13, 2017. Warmbier, serving a 15-year prison term for alleged anti-state acts, was released and medically evacuated from the reclusive country Tuesday and has been in a coma for months, his parents said. (AP Photo/John Minchillo)

Denise Koesterman, right, and Alison Lebrun, left, tie blue-and-white awareness ribbons along Springfield Pike near the family home of Otto Warmbier, a 22-year-old University of Virginia undergraduate student who was imprisoned in North Korea in March 2016, in the Wyoming suburb of Cincinnati on Tuesday, June 13, 2017. Warmbier, serving a 15-year prison term for alleged anti-state acts, was released and medically evacuated from the reclusive country Tuesday and has been in a coma for months, his parents said. (AP Photo/John Minchillo)