The Justice Department, on behalf of the Pentagon, on Tuesday asked an appeals court to block an effort to enforce plea deals reached with four accused conspirators of the Sept. 11, 2001, terrorist attacks.

Khalid Sheikh Mohammed, Mustafa al Hawsaw, and Walid bin Attash can plead guilty to the terrorist attack and avoid the death penalty.

The U.S. government earlier this year entered into the plea agreements with Khalid Sheikh Mohammed and two other 9/11 suspects, sparing them the death penalty.

It comes days before the accused 9/11 mastermind’s scheduled guilty plea in an agreement that would spare him the death penalty.

A military appeals court has ruled against Defense Secretary Lloyd Austin’s effort to throw out the plea deals reached for Khalid Sheikh Mohammed and two other defendants in the 9/11 attacks, a US official said.