Abdella Ahmad Tounisi's lawyer asked at a hearing to in Chicago for her client to be released to home confinement.
Molly Armour argued that Tounisi was an immature 18-year-old when he was arrested at O'Hare International Airport in 2013 trying to board a plane to Turkey.
She argued that his stint in jail since has been "a maturing process."
But prosecutor William Ridgway countered that jail may have actually hardened Tounisi's anti-American views.
Judge Samuel Der-Yeghiayan said he saw no compelling reason to revisit the detention issue.
Tounisi is charged with material support for terrorism.