Alexandria, Virginia (CNN) Ali Shukri Amin, from Alexandria, Virginia, pleaded guilty Thursday in a federal court to providing material support to ISIS and faces up to 15 years in prison when he is sentenced Aug. 28.

The 17-year-old was accused of helping, Reza Niknejad, 18, who officials believe went on to join ISIS, travel to Syria, a law enforcement source said in March. The teen was also accused of passing messages between ISIS contacts.

Amin appearing before the judge in a blue jail jumpsuit only responded "guilty sir" to the judge when asked to give his plea and "no sir" when asked if he is innocent in any way to the charges he is facing.

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Amin admitted in a statement of fact as part of the plea agreement to using the twitter handle @Amreekiwitness to "provide advice and encouragement to ISIL and its supporters," according to a Department of Justice press release.

Additionally, Amin taught followers how to use bitcoin to covertly send funds to the terror group.