Three of the men accused of plotting the 9/11 attacks on the US have entered into a pre-trial agreement.
Khalid Sheikh Mohammed, Walid Muhammad Salih Mubarak Bin Attash, and Mustafa Ahmed Adam al-Hawsawi were all held at Guantanamo Bay without going to trail.
The US Department of Defence claimed details of the deal had not yet been announced.
However, local reports suggested a guilty plea came in exchange for the prosecution agreeing not to seek the death penalty.
An image of the 9/11 attackGETTYThe 2001 attack resulted in nearly 3,000 people being killed in New York, Virginia and Pennsylvania.
It was the deadliest attack on US soil since Japan attacked Pearl Harbour in 1941.
The attack on Hawaii, which led Franklin Delano Roosevelt to take the US to war, resulted in 2,400 people being killed.
Defendants will make a plea before a military court could come as early as next week.
LATEST DEVELOPMENTS:The US defence department said "the specific terms and conditions of the pretrial agreements are not available to the public at this time".
The trio were accused of several charges, including attacking civilians, murder in violation of the laws of war, hijacking and terrorism.
Mohammed is widely considered the architect of the attack.
He was captured along with Hawsawi in Pakistan in March 2003.
Mohammed was accused of raising the idea of hijacking and flying planes into US buildings to al-Qaeda leader Osama Bin Laden.
He was subjected to a number of "enhanced interrogation techniques", including waterboarding.
However, the practice was later banned by the US Government.
The plea deal comes just months after Joe Biden's administration rejected the terms of a plea deal with five men held at the US Navy base in Cuba, including Mohammed.
Khalid Sheikh Mohammed is one of the three men who reached a plea deal
GETTYThe White House National Security Council said that the president's office was told on Wednesday of the new deal and had played no role in negotiations.
Republicans have pounced on reports of a plea deal for 9/11 terrorists.
Senate Minority Leader Mitch McConnell condemned the move as "a revolting abdication of the government's responsibility to defend America and provide justice".
"The only thing worse than negotiating with terrorists is negotiating with them after they are in custody," he said.