A Libyan militant on Monday pleaded not guilty to charges arising from the 2012 Benghazi attacks that killed four Americans, including U.S. Ambassador Chris Stevens.

Ahmed Abu Khatallah, 43, entered the plea through his lawyer in a 15-minute court proceeding before a federal judge.

An 18-count grand jury indictment handed up last week makes Abu Khatallah eligible for the death penalty if convicted.

Abu Khatallah's lawyer, federal public defender Michelle Peterson, said she is waiting for the Justice Department to turn over additional material -- much of it classified -- on the charges her client faces. The next court date in the case was set for Dec. 9.

Khatallah's lawyer has said previously that the government has failed to show Khatallah was connected to the attacks.

The charges against him include murder of an internationally protected person, murder of an officer and employee of the United States and killing a person in the course of an attack on a federal facility.

Abu Khatallah is the first militant to be prosecuted for the Benghazi attacks.

The Sept. 11, 2012, attack by militants killed Stevens and communications specialist Sean Smith and set the mission ablaze.

Nearly eight hours later at a CIA complex nearby, two more Americans, contract security officers Tyrone Woods and Glen Doherty, died in a mortar attack that showed clear military training, retired Gen. Carter Ham told Congress in closed-door testimony earlier this year.

The administration apprehended Abu Khatallah in June and brought him to the United States to stand trial on terrorism charges.