A Wisconsin man pleaded not guilty Friday to a federal charge that he tried to join the Islamic State terror group.

Prosecutors charged Joshua Van Haften in October with trying to provide material assistance to a foreign terrorist group. A grand jury indicted the 34-year-old on Thursday. And on Friday, public defender Joseph Bugni entered a not guilty plea on Van Haften’s behalf during a 10-minute court session.

Van Haften, a convicted sex offender, sat quietly at the defense table in a blue jail jumpsuit, his hair hanging to his shoulders. Bugni did not speak to reporters.

U.S. Magistrate Judge Stephen Crocker set a status conference for May 27.

Online state court records show Van Haften was convicted of second-degree child sexual assault in 1999 and sentenced to seven years in prison. His mother’s partner, Howard Whitledge, told the Wisconsin State Journal newspaper that Van Haften turned to Islam while he was incarcerated.

According to federal court documents, Van Haften flew to Turkey in August. In October he posted comments on Facebook saying he was in Istanbul waiting for a contact to take him into Syria along with a photo of a room with bags sitting in the corner. He also posted comments saying some men took him out into the countryside and left him there, promising someone would come for him. After three hours of waiting he walked to a village, where an imam paid for him to return to Istanbul.

The documents note multiple Facebook postings in which Van Haften expresses his support for IS, Islamic extremists and his impatience to join them.

He was arrested on April 8 at O’Hare International Airport in Chicago after flying back from Turkey.

Van Haften could face up to 15 years in prison, $250,000 in fines and three years on supervised release if he’s convicted.