Five men being held in Guantanamo Bay prison accused of planning and aiding the September 11 terror attacks will go on trial in 2021.
If convicted at the military commission, which combines elements of civilian and military law, the defendants could face the death penalty.
The five detainees include Khalid Shaikh Mohammed, a senior al Qaeda figure who has portrayed himself as the mastermind of the 2001 attacks and other terrorist plots.
The US has charged the five with war crimes that include terrorism, hijacking and nearly 3,000 counts of murder for their alleged roles planning and providing logistical support to the attacks.
Air Force Colonel W. Shane Cohen set a start date of 11 January 2021 in order to set in motion deadlines for evidence to be submitted. The war crimes trial has been long-stalled in a case that has been bogged down in pre-trial litigation.
Mohammed and his four co-defendants have been held at the US base Guantanamo Bay, Cuba, since September 2006 after several years in clandestine CIA detention facilities following their capture.
The five defendants had their charges formally read to them in May 2012, six years after their arrival at Guantanamo bay.
Mr Cohen noted that the trial at Guantanamo Bay "will face a host of administrative and logistics challenges".