U.S. President Donald Trump condemned the "brutality" of the North Korean regime following the death Monday of university student Otto Warmbier, who was released by the country last week in a coma after more than 17 months' imprisonment.

Warmbier died at the Ohio hospital where he was being treated, his family said in a statement. "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," the family said.

Warmbier, 22, returned to his home state of Ohio last Tuesday after being detained in North Korea over what Pyongyang said was an attempt to steal an item bearing a propaganda slogan.

Doctors treating him at the University of Cincinnati Medical Center said Thursday he had a severe brain injury, but it was not clear what caused it.

In a statement issued Monday, Trump said the United States "once again condemns the brutality of the North Korean regime as we mourn its latest victim."

"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 statement said.

North Korea claimed the University of Virginia student was in a coma for almost all of the time he was detained, according to Fred Warmbier, Otto's father.

Warmbier, detained in January 2016, was serving a 15-year prison term with hard labor. He was visiting North Korea with a tour group.

Warmbier was convicted for what North Korea said was a hostile act against its regime in his attempt to steal an item with a propaganda slogan in a staff-only area of his hotel.

Speaking to reporters in Washington on Monday, Susan Thornton, acting assistant secretary of state for East Asian and Pacific Affairs, said the United States is concerned about the welfare of three other Americans held in North Korea.

"We definitely would like to see them return home as soon as possible," Thornton said.

Following Warmbier's death, China-based Young Pioneer Tours said it will no longer organize trips to North Korea for U.S. citizens and said a "tragedy like this must never be repeated."

"The devastating loss of Otto Warmbier's life has led us to reconsider our position on accepting American tourists," the travel group said in a statement on its website, calling the handling of his detention "appalling."

It said that after Warmbier was held, it constantly requested a chance to meet the student or anyone in contact with him in Pyongyang, but was denied that, "only receiving assurances that he was fine."

"There had not been any previous detainment in North Korea that has ended with such tragic finality and we have been struggling to process the result. Now, the assessment of risk for Americans visiting North Korea has become too high," Young Pioneer Tours said.