Secretary of State Mike Pompeo called the release of John Walker Lindh, dubbed the "American Taliban," an "unexplainable and unconscionable" decision.

The captured Islamic militant, who at age 20 journeyed to Afghanistan to join the Taliban and fought alongside the terrorists in the days after 9/11, was released from a federal prison in Indiana on Thursday morning just as Pompeo was speaking on "Fox & Friends."

Lindh was discharged several years before completing the 20-year prison sentence he received for joining and supporting the Taliban, with officials citing "good behavior" for the early release.

DAUGHTER OF AMERICAN KILLED AFTER SPEAKING WITH LINDH SLAMS UPCOMING EARLY RELEASE

The former Islamist fighter and enemy combatant, named “Detainee 001 in the war on terror,” was captured alongside a group of Taliban fighters in 2001, just months after the Sept. 11, 2001, attacks and the start of the war in Afghanistan.

Lindh has been blamed for playing a role in the death of Johnny “Mike” Spann, a U.S Marine turned CIA paramilitary operative who became the first American to be killed in combat in Afghanistan. Spann’s daughter, Allison, told Fox News in March that Lindh’s early release “feels like such a slap in the face.”

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Pompeo, who previously served as CIA director under President Trump, said Spann "was one of ours" and someone of "enormous integrity and courage."

"We're now allowing someone who was involved in his death out of jail after what is a relatively short sentence," said Pompeo, calling for a review of the procedures that led to Lindh's release.

He said he cannot account for how the decision could be made when Lindh has been unrepentant about his support for terrorists.