"Prosecuting the 9/11 defendants in federal court does not represent some larger judgment about whether or not we are at war. We are at war, and we will use every instrument of national power - civilian, military, law enforcement, intelligence, diplomatic, and others - to win," said Holder.
Critics of holder's decision have argued the trial will give Mohammed a global stage to spout hateful rhetoric.
"I have every confidence the nation and the world will see him for the coward he is," said Holder.
The ranking Republican on the Senate Judiciary Committee accused holder of returning to a "pre-9/11 mentality".
"These people captured on the battlefield are not common criminals? I believe this decision is dangerous, misguided, and unnecessary," said Senator Jeff Session (R) Alabama.
But the committee chairman said trying terrorists in civilian courts sends the right message to the international community.
Senator Patrick Leahy (D) Vermont said, "We do not jury-rig secret trials or kangaroo courts. We can rely on the American justice system."
Senator Charles Schumer of New York is asking the Attorney General to ensure that New York City will be reimbursed for any security expenses associated with the trials which is expected to cost at least $75 million dollars.