WASHINGTON — Defense Secretary Lloyd Austin on Friday overrode a plea agreement reached earlier this week for the accused mastermind of the September 11, 2001, attacks and two other defendants, reinstating them as death-penalty cases.

The move comes two days after the military commission at Guantanamo Bay, Cuba, announced that the official appointed to oversee the war court, retired Brig. Gen. Susan Escallier, had approved plea deals with Khalid Sheikh Mohammed and two accused accomplices, Walid bin Attash and Mustafa al-Hawsawi, in the attacks.

Letters sent to families of the nearly 3,000 people killed in the al-Qaida attacks said the plea agreement stipulated the three would serve life sentences at most.

Austin wrote in an order released Friday night that “in light of the significance of the decision,” he had decided that the authority to make a decision on accepting the plea agreements was his. He nullified Escallier’s approval.

Some families of the attack’s victims condemned the deal for cutting off any possibility of full trials and possible death penalties. Republicans were quick to fault the Biden administration for the deal, although the White House said after it was announced it had no knowledge of it.

Republican Sen. Tom Cotton of Arkansas, a member of the Armed Services Committee, earlier Friday had condemned the plea deal on social media as “disgraceful.” Cotton said he had introduced legislation that would mandate the 9/11 defendants face trial and the possibility of the death penalty.

Mohammed, whom the U.S. describes as the main plotter of the attack that crashed hijacked passenger planes into the World Trade Center, the Pentagon, and a Pennsylvania field, and the other two defendants had been expected to formally enter their pleas under the deal as soon as next week.

The U.S. military commission overseeing the cases of five defendants in the September 11 attacks has been stuck in pre-trial hearings and other preliminary court action since 2008. The torture that the defendants underwent while in CIA custody has been among the challenges slowing the cases, and left the prospect of full trials and verdicts still uncertain, in part because of the inadmissibility of evidence linked to the torture.

J. Wells Dixon, a staff attorney at the Center for Constitutional Rights who has represented defendants at Guantanamo as well as other detainees there who have been cleared of any wrongdoing, had welcomed the plea bargains as the only feasible way to resolve the long-stalled and legally fraught 9/11 cases.

Dixon accused Austin on Friday of “bowing to political pressure and pushing some victim family members over an emotional cliff” by rescinding the plea deals.

Lawyers for the two sides have been exploring a negotiated resolution to the case for about 1 1/2 years. President Joe Biden blocked an earlier proposed plea bargain in the case last year, when he refused to offer requested presidential guarantees that the men would be spared solitary confinement and provided trauma care for the torture they underwent while in CIA custody.

A fourth September 11 defendant at Guantanamo had been still negotiating on a possible plea agreement.

The military commission last year ruled the fifth defendant mentally unfit to stand trial. A military medical panel cited post-traumatic stress disorder and psychosis, and linked it to torture and solitary confinement in four years in CIA custody before transfer to Guantanamo. — Agencies