Ghani's speech came as his government attempts to revive a moribund talks process with the Taliban, whose 13-year insurgency has gained significant momentum with the phased withdrawal of US-led NATO combat troops in the country.
"The Afghan government condemns these inhumane actions in the strongest terms," he said at a specially-convened press conference at the presidential palace in Kabul.
"There can be no justification for these kinds of actions and inhumane torture in today's world."
Ghani, who took office in September amid hopes of better bilateral relations with the US than those enjoyed by his predecessor Hamid Karzai, said: "The reason I want to talk to my countrymen tonight is to explain our position on that report released by the US Senate.
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"This report is 499 pages long and since downloading it from the Internet last night I have read every single word of it.
"This is a vicious cycle. When a person is tortured in an inhumane way, the reaction will be inhumane. And thus a vicious cycle of action and reaction is created."
Prison facilities at Bagram were mainly handed over to Afghan control in 2012, though the United States is still in charge of foreign detainees.
One Pakistani inmate who was interviewed by AFP in April said he suffered beatings, sleep deprivation and a sustained campaign of mental disintegration over nine years despite committing no crime.
An official record of his detention that was later made unclassified shows his captors suspected the same.
"We want the number of these Afghans to be known, we want their names to be released so we take action for their rights and to defend their human dignity in a serious and fundamental way.