September 11, 2001, attack on the World Trade Center
September 11, 2001, attack on the World Trade CenterREUTERS/Sean Adair/File

The Biden administration successfully delayed a guilty plea by Khalid Sheikh Mohammed, the alleged mastermind behind the Sept. 11, 2001, terrorist attacks, following a federal appeals panel's decision on Thursday to issue a temporary stay, The Associated Press reported.

This move halts a plea deal that would have spared Mohammed the death penalty.

Administration attorneys petitioned the court to prevent the plea from proceeding as planned on Friday at Guantanamo Bay, Cuba. Defense lawyers criticized the move, calling it another example of two decades of "fitful" and "negligent" case handling by the US government.

The appeals panel clarified that the stay is temporary, allowing time to fully review the administration’s arguments. The decision, however, does not represent a final judgment on the matter.

The Biden administration’s actions have created tension with U.S. military officials, including those it appointed to oversee proceedings related to the 9/11 attacks. Defense Secretary Lloyd Austin, speaking after a meeting in Germany, reaffirmed his opposition to the plea agreement but declined further comment, citing ongoing legal proceedings.

The plea deal, which took two years to negotiate and was approved by military prosecutors and a senior Pentagon official in July, would eliminate the death penalty risk for Mohammed and two co-defendants. In exchange, the defendants would provide information to help answer lingering questions from victims' families.

Last week, a military appeals court ruled against Austin’s attempt to nullify the plea agreements.

Defense attorneys argue the agreements are legally binding and cannot be overturned unilaterally by Austin. Preparations for Friday’s proceedings had continued after the appeals court’s decision, with Mohammed expected to formally plead guilty to 2,976 counts of murder and other charges. Pleas from co-defendants Walid bin Attash and Mustafa al Hawsawi were scheduled for later this month.

Earlier this summer, military prosecutors informed victims’ families that the plea deal offered “the best path to finality and justice.” However, Austin announced in August that he was overturning the agreement, arguing that decisions on the death penalty for such a grave attack should rest solely with the defense secretary.

The Justice Department argued that allowing the guilty pleas to proceed would cause "irreparable harm" by forgoing a public trial and the opportunity to seek the death penalty for what it described as “a heinous act of mass murder.”