GUANTÁNAMO BAY, Cuba (Reuters) — The man accused of being the mastermind of the Sept. 11 attacks said in a courtroom here on Wednesday that the United States government had killed many more people in the name of national security than he was accused of killing.

The defendant, Khalid Shaikh Mohammed, was allowed to address the court at a pretrial hearing focused on security classification rules for evidence that will be used in his trial on charges of orchestrating the attacks by hijacked planes.

“When the government feels sad for the death or the killing of 3,000 people who were killed on Sept. 11,” he said, there should also be sorrow that the government has killed “thousands of people, millions.”

Mr. Mohammed, who wore a military-style camouflage vest to the courtroom, accused the United States of using an elastic definition of national security, comparable to the way dictators bend the law to justify their acts.