US defence secretary Lloyd Austin says he did not agree to deal and relieves officer overseeing court of authority.

US Defense Secretary Lloyd Austin has revoked a pre-trial agreement reached with men accused of plotting the 11 September terrorist attacks.

In a memo on Friday, Mr Austin also said he was revoking the authority of the officer overseeing the court who signed the agreement on Wednesday.

The original deal, which would reportedly have spared the alleged attackers the death penalty, was criticised by some families of victims.

The memo named five defendants including the alleged ringleader of the plot, Khalid Sheikh Mohammed. The original deal named three men.

“I have determined that, in light of the significance of the decision to enter into pre-trial agreements with the accused… responsibly for such a decision should rest with me as the superior authority,” Mr Austin wrote to Brig Gen Susan Escallier.

“I hereby withdraw your authority. Effective immediately, in the exercise of my authority, I hereby withdraw from the three pre-trial agreements.”