The Pentagon chief was caught off guard by last week’s decision by prosecutors to offer deals to the men.
The US defence secretary has revoked plea deals with Khalid Sheikh Mohammed and two alleged accomplices.
Mohammed and two other defendants likely to enter formal plea next week over attacks that killed nearly 3,000 people.
Incompetency finding for Ramzi bin al-Shibh means the prosecution of his four co-defendants would continue without him.
Threat of attacks has receded, but experts believe a regeneration of hardline groups in the region is still possible.
The Democratic president, angling for reelection in 2024, called for unity ‘regardless of our political backgrounds’.
Twenty years on from the start of the Iraq war, we look at how the US and UK media helped sell the war to the public.
Never charged with a crime, Ghassan Al Sharbi, 48, returns to Saudi Arabia after being held for 21 years at Guantanamo.
![The exterior of Camp Delta is seen at the US Naval Base at Guantanamo Bay [REUTERS]](https://www.aljazeera.com/wp-content/uploads/2016/02/8f78ac8701b149948f11082f2c055312_18.jpeg?resize=770%2C513&quality=80)
Majid Khan, who was tortured by the CIA before his transfer to the US military facility in Cuba, says he feels ‘reborn’.
US observes the 21st anniversary of the 9/11 attacks, as New Yorkers honour the nearly 3,000 killed in September 2001.
The September 11, 2001 attacks on the United States ushered in a new era of hate crimes and racism.
Relatives of the nearly 3,000 victims have long hoped a trial would bring closure and resolve unanswered questions.
Al-Zawahiri, linked to 9/11 and attacks that left thousands dead, has been killed in a US drone strike.
The settlement with the Justice Department includes $98,000 to be split among the six men who filed the lawsuit.
