The deal for the guilty pleas by Khalid, Walid bin Attash and Mustafa al-Hawasawi rather than a death penalty trial has been approved by a senior Pentagon official, the Times said.

All three men have been in custody since 2003. Khalid is an al-Qaeda militant accused by the US of being the principal architect of the Sept 11 attacks on New York’s World Trade Center and the Pentagon outside Washington.

“In exchange for the removal of the death penalty as a possible punishment, these three accused have agreed to plead guilty to all of the charged offences, including the murder of the 2,976 people listed in the charge sheet,” the chief prosecutor, Rear Admiral Aaron Rugh, said in a letter to family members of Sept 11 victims, according to the Times.

The letter said the men could submit their pleas in open court as early as next week, according to the Times. The defence department released a statement on Wednesday saying prosecutors had reached plea agreements with Khalid, Walid and al-Hawasawi, without disclosing the terms of those deals.