URBANA, Illinois - A man accused of kidnapping Chinese visiting scholar Zhang Yingying will face trial on Sept 12 after he pleaded not guilty on Thursday in a federal court in Urbana, Illinois.

Brendt Christensen, 28, of Champaign, who has a master's degree in physics from the University of Illinois at Urbana-Champaign, was indicted eight days ago after his arrest on June 30 on a charge of kidnapping Zhang, 26, who attended the same school.

Zhang has not been seen since she was captured by security camera entering the passenger seat of the car of the suspect on June 9. Police believe that she is no longer alive.

Unlike two prior hearings, Christensen spoke at the brief proceeding. He said he took the drug Klonopin, an antidepressant, when asked by US Magistrate Judge Eric Long if he took any medication in the Macon County Jail, where he is being kept without bail.

He said the medication did not affect his ability to understand the charges against him, according to The News-Gazette.

Anthony Bruno, one of Christensen's attorneys, said after the proceeding that the defendant has demanded a jury trial and "plans to persist in his plea of not guilty".

Bruno said the defense will receive discovery information in the next few weeks from the US attorney's office.

"I think this case could go on a year or more," he said.

No new evidence was presented at the arraignment on Thursday, which was attended by Zhang's family members. A pretrial hearing was set for Aug 28.

Wang Zhidong, a lawyer representing members of Zhang's family, said he is certain the trial will be delayed.

"The Speedy Trial Act (1974) requires that a trial must be set within 70 days, but either side might file motions requesting more time," Wang said.

"The investigation is still ongoing, and both prosecutors and defense attorneys may have discoveries," he said. "Prosecutors have some pieces of evidence that haven't gone public."

Wang said that after the arraignment Thursday, Judge Long would pass the case to US District Court Judge Colin S. Bruce.

A former US attorney in the Central District of Illinois before becoming a judge, Bruce handled more than 600 cases in federal court, including 60 jury trials and 80 appeals. He was nominated for the District Court by President Barack Obama in 2013 and confirmed by the US Senate the same year.

Wang also said Zhang's family members would not return to China without her and are hopeful they will bring her home.

Liu Jun, acting Chinese consul general in Chicago, who attended the arraignment, said the Chinese Consulate General in Chicago will follow the case closely and continue to provide assistance to Zhang's family.

"We urge the police to make this case a priority, mobilize all resources and think outside of the box to find Yingying as soon as possible," Liu said. "We hope the Justice Department will conduct a fair trial."