CHICAGO (AP) — A suburban Chicago teenager has pleaded not guilty to charges he sought to join an al-Qaida-linked militant group fighting Bashar Assad's regime in Syria.

Abdella Ahmad Tounisi's (too-NEE'-seez) attorney entered the plea Wednesday at a federal court in Chicago. The 18-year-old Tounisi stood by her side in orange jail garb, his legs shackled.

Authorities arrested Tounisi in April at O'Hare International Airport as he allegedly prepared for the first leg of a trip to join Jabhat al-Nusrah.

Tounisi pleaded not guilty to attempting to provide material support to a foreign terrorist organization and lying to federal authorities.

If convicted, he faces a maximum 23-year prison term.