A trial date for the alleged architect of the 9/11 attacks has been set.
Khalid Sheikh Mohammed will be tried along with four other men at a military court in Guantanamo Bay from January 11, 2021.
The men are being held at the prison base in Cuba on charges of planning and aiding the September 11, 2001 terrorist attacks on the US.
Air Force Colonel W Shane Cohen set the start date in an order setting motion and evidentiary deadlines in a case that has been bogged down in pretrial litigation.
The five defendants were arraigned in May 2012.
In setting the January 11 2021, start, Mr Cohen noted that the trial at the US base at Guantanamo Bay, Cuba, "will face a host of administrative and logistics challenges".
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 September 11 plot.
They could get the death penalty if convicted at the military commission, which combines elements of civilian and military law.
Mohammed is a senior al-Qaida figure who has portrayed himself as the mastermind of the September 11 attacks and other terrorist plots.
He was captured in Pakistan in 2003.
He and his four co-defendants have been held at Guantanamo since September 2006 after several years in clandestine CIA detention facilities following their capture.
In a previous attempt to try Mohammed in 2008, he said he planned to plead guilty and welcomed martyrdom.
In 2009, the Obama administration, which wanted to close Guantanamo, attempted to move the trial to New York but later reversed its decision after opposition from Congress.
Prosecutors say Mohammed was involved in a number of terrorist activities, including the 2002 Bali nightclub bombing, the 1993 World Trade Center bombing and the murder of US journalist Daniel Pearl.
Defence lawyers for Mohammed and the four other men - Walid bin Attash, Ramzi bin al-Shibh, Ammar al-Baluchi and Mustafa al-Hawsawi - want to bar the use of confessions made to the FBI in 2006, claiming they are unusable because they were gained from harsh interrogation.