SEOUL, South Korea — North Korea responded for the first time on Friday to American accusations that it had fatally brutalized Otto F. Warmbier, the captive college student, asserting he was given medical treatment and treated with respect even though he was a “criminal of the enemy state.”

Mr. Warmbier, 22, who was released in a coma by the North Koreans on June 13 after 17 months of captivity and returned to his family in Ohio, died less than a week later. His death outraged the United States and worsened already-poor American relations with North Korea.

American doctors who examined him after his return home reported extensive brain damage but could not explain what caused the injury.

On Friday, a spokesman of the North’s Foreign Ministry issued a statement denying that Mr. Warmbier had been abused or tortured.

“Although we had no reason at all to show mercy to such a criminal of the enemy state, we provided him with medical treatment and care with all sincerity on a humanitarian basis until his return to the U.S., considering that his health got worse,” said the statement, carried by the North’s official Korean Central News Agency.

Mr. Warmbier was arrested in the North in January 2016 while visiting the country on a tourist visa. Two months later, he was sentenced to 15 years of hard labor, accused of committing a “hostile act” by trying to steal a political poster from his hotel in Pyongyang, the capital.

His coma and subsequent death have set off outrage in the United States. President Trump condemned the North’s “brutality,” and other political leaders demanded that it explain what happened to Mr. Warmbier.

Until Friday, North Korea had said only that it released the young man on “humanitarian grounds.” It told American officials that Mr. Warmbier had contracted botulism and fallen into a coma after taking sleeping pills, according to his family, which was briefed by the officials. The family rejected that explanation, saying he had been “brutalized and terrorized.”

On Friday, the Foreign Ministry spokesman did not disclose what caused Mr. Warmbier’s coma. But the spokesman, whom state news did not identify, said that American doctors who flew to Pyongyang to evacuate Mr. Warmbier recognized that the North had “provided him with medical treatment and brought him back alive” after his “heart was nearly stopped.”

The spokesman said North Korea could not understand why Mr. Warmbier died so suddenly after returning home because his health indicators were “normal” upon his release. “To make it clear, we are the biggest victim of this incident,” he said, calling the accusations of abuse “groundless.”

The spokesman also said Mr. Warmbier was “a victim of the policy of strategic patience,” referring to President Barack Obama’s policy of focusing on sanctions and applying pressure on the North. He said that North Korea had accepted the Trump administration’s “repeated requests” for Mr. Warmbier’s release and, “in consideration of his bad health, sent him back home on humanitarian grounds.”

He warned that the “smear campaign” against the North compelled it to “make firm determination that humanitarianism and benevolence for the enemy are a taboo and we should further sharpen the blade of law.”

North Korea still holds three Americans, all of them ethnic Koreans. Since Mr. Warmbier’s death, Washington has repeatedly urged the North to release them. One of them, Kim Dong-chul, 63, has been serving a 10-year sentence of hard labor since April 2016 on spying charges. North Korea has yet to announce formal charges against the other two, Tony Kim and Kim Hak-song, who were detained for unknown reasons in April and May.

The funeral for Mr. Warmbier was held on Thursday in the high school he attended in Wyoming, Ohio. According to his family’s wishes, no autopsy was performed.