A trial date has reportedly been set for the alleged mastermind of the 9/11 attacks on the United States, Khalid Sheikh Mohammad.
The New York Times says he will be tried in a military court in Guantanamo Bay along with four others, from January 2021.
He has already been detained for more than 15 years.
The men have been charged with the murders of nearly 3000 people, who died when planes crashed into New York's twin towers, the Pentagon and another that came down in Pennsylvania.
The United States government is seeking the death penalty.
AFP quotes the newspaper report as saying that a military judge at the US Navy's Guantanamo, Cuba base set the date for the trial for 11 January, 2021.
Mohammad, Walid bin Attash, Ramzi Binalshibh, Ali Abd al-Aziz Ali, and Mustafa al-Hawsawi were accused of planning and participating in the plot hatched by al-Qaeda leader Osama bin Laden to hijack four airliners and crash them into New York's World Trade Centre and buildings in Washington.
The five men will be the first to go on trial, nearly 20 years since the devastating attacks in New York, Washington and Pennsylvania.
Two of the planes struck the World Trade Centre, another hit the Pentagon and a fourth crashed into a field in Pennsylvania after passengers, having learned of the other flights, fought the hijackers.
The five were formally charged in 2012 with conspiracy, attacking civilians, murder in violation of the law of war, aircraft hijacking and terrorism.
Mohammad, a Pakistan native thought to be about 54, is a key figure in the trial: he has been accused of being the mastermind of the 9/11 plot.
He was captured in Pakistan in 2003. But attempts to prosecute him and the rest of the group have been mired in delays.
During an earlier attempt to try him before a military tribunal in 2008, he said he intended to plead guilty and would welcome martyrdom.
In 2009 the Obama administration, which had pledged to close Guantanamo, tried to move the trial to New York but reversed its decision in 2011 after opposition from Congress.
The five men were eventually charged in June 2011 with offences similar to those they were accused of by George W Bush's administration.
The Pentagon has previously said Khalid Sheikh Mohammed admitted he was responsible "from A to Z" for the 9/11 attacks.
Mohammad responsible for other terrorist attacks, US says
US prosecutors allege that he was involved with a host of other terrorist activities.
These include the 2002 nightclub bombing in Bali, Indonesia; the 1993 World Trade Centre bombing; the murder of American journalist Daniel Pearl; and a failed 2001 attempt to blow up an airliner using a shoe bomb.
Hearings for the forthcoming trial are planned for next month.
Lawyers for the group are trying to bar the use of confessions the defendants made to the FBI in 2006.
They argue that the confessions are unusable in court because of the harsh interrogations carried out during their detention.
Khalid Sheikh Mohammed has alleged that he has been repeatedly tortured during his detention in Cuba.
CIA documents confirm that he was subjected to simulated drowning, known as waterboarding, 183 times.
The four other men were also interrogated by the CIA in a network of overseas prisons, known as "black sites," before they were passed on to the US military.
-BBC / AFP