(CNN) — Otto Warmbier, the American college student who spent 17 months in detention in North Korea, died Monday afternoon in Cincinnati, Ohio, his family said in a statement.

“It is our sad duty to report that our son, Otto Warmbier, has completed his journey home. Surrounded by his loving family, Otto died today at 2:20 p.m.,” the statement said.

The 22-year-old returned to the United States last week and has not spoken or moved in any purposeful way since. In a news conference last Thursday, doctors called his condition “unresponsive wakefulness,” also known as persistent vegetative state, and revealed he had suffered significant brain damage during his imprisonment.

The North Korean government said the student fell into a coma after contracting botulism and taking a sleeping pill in March 2016. But US doctors said they found no evidence of the illness.

The family expressed anger at his treatment in North Korea.

“We would like to thank the wonderful professionals at the University of Cincinnati Medical Center who did everything they could for Otto. Unfortunately, the awful torturous mistreatment our son received at the hands of the North Koreans ensured that no other outcome was possible beyond the sad one we experienced today.”

President Donald Trump expressed dismay at news of Warmbier’s death and condemned the “brutal regime.”

“Melania and I offer our deepest condolences to the family of Otto Warmbier on his untimely passing. There is nothing more tragic for a parent than to lose a child in the prime of life. Our thoughts and prayers are with Otto’s family and friends, and all who loved him,” he said in a statement.

“Otto’s fate deepens my Administration’s determination to prevent such tragedies from befalling innocent people at the hands of regimes that do not respect the rule of law or basic human decency. The United States once again condemns the brutality of the North Korean regime as we mourn its latest victim.”

Trip ends in allegations

Warmbier signed up for a trip to North Korea in spring 2016 with the Young Pioneer Tours travel group. He was supposed to spend five days in North Korea followed by a visit to Beijing.

But as he tried to depart from Pyongyang’s airport, he was stopped in security.

According to the North Korean government, Warmbier was detained because he had stolen a political poster from a restricted floor in his hotel. The next time the world saw Warmbier he was distraught, breaking down in front of Korean journalists in a video released by North Korea in February 2016.

He admitted to the crime and begged for forgiveness and for his release. Warmbier was sentenced to 15 years of hard labor for his alleged crime. In the end, he spent 17 months in North Korea before he was released and returned to the United States by a medical aircraft.

How the US secured his release

While Warmbier was held, the United States consistently urged North Korea to allow Sweden consular access to Warmbier and three other American citizens, and pushed for their release.

After being briefed on the situation, Trump directed Secretary of State Rex Tillerson to take appropriate measures to secure the release of American hostages there, a senior State Department official told CNN. Tillerson began the effort and routinely updated the President.

Then, on June 6, State Department special representative Joseph Yun learned of Warmbier’s deteriorating health in a meeting with North Korean UN Mission Ambassador Pak Kil-yon in New York City, the senior State Department official said.

Yun went to North Korea on June 12 with a medical team to secure Warmbier’s release, the official said. Yun and two doctors visited Warmbier that morning, marking the first time the US was able to confirm his status since he was sentenced in March 2016. Yun immediately demanded that Warmbier be released on humanitarian grounds and arrangements were made for him to leave.

He was evacuated the next day and reunited with his family in Cincinnati.

“When Otto returned to Cincinnati late on June 13th he was unable to speak, unable to see and unable to react to verbal commands. He looked very uncomfortable — almost anguished. Although we would never hear his voice again, within a day the countenance of his face changed — he was at peace. He was home and we believe he could sense that,” the family’s statement said.

“It would be easy at a moment like this to focus on all that we lost — future time that won’t be spent with a warm, engaging, brilliant young man whose curiosity and enthusiasm for life knew no bounds. But we choose to focus on the time we were given to be with this remarkable person.”