Updated

Prosecutors want the maximum 15-year prison term for a young Chicago-area man who sought to join an al-Qaida-linked group fighting Bashar Assad's regime in Syria.

They requested the sentence in a court filing Thursday for Abdella Ahmad Tounisi's (too-NEE'-see), who was 18 when arrested in an FBI internet sting in 2013. He has pleaded guilty to attempting to offer material support to foreign terrorists.

Tounisi's lawyers want a seven-year term. They say their client felt isolated as a Muslim in the U.S. and that his decision to travel to Syria reflected his immaturity. They insist he's tried to change since then.

Prosecutors say Tounisi persisted even after a friend was arrested on terrorism charges in 2012, and after relatives expressed concern about his interest in Syria.

Sentencing is Oct. 19.