From opposite ends of the globe, President Barack Obama and Attorney General Eric Holder firmly rejected criticism Wednesday of the planned New York trial of the professed Sept. 11 mastermind and predicted Khalid Sheikh Mohammed would be exposed as a murderous coward, convicted and executed.

"Failure is not an option," Holder declared.

The president, in a series of TV interviews during his trip to Asia, said those offended by the legal rights accorded Mohammed by virtue of his facing a civilian trial rather than a military tribunal won't find it "offensive at all when he's convicted and when the death penalty is applied to him."

Obama, who is a lawyer, quickly added that he did not mean to suggest he was prejudging the outcome of Mohammed's trial. "I'm not going to be in that courtroom," he said. "That's the job of the prosecutors, the judge and the jury."

The president said in interviews broadcast on NBC and CNN that experienced prosecutors in the case who specialize in terrorism have offered assurances that "we'll convict this person with the evidence they've got, going through our system."

In Washington, the Senate Judiciary Committee questioned Holder for hours about his decision to send Mohammed and four others from the U.S. military detention center at Guantanamo Bay, Cuba, to New York for trial in a federal courthouse blocks from the site of the World Trade Center towers destroyed in the 9/11 attacks in 2001.

The attorney general said he is certain the men will be convicted, but even if a suspect were acquitted, "that doesn't mean that person would be released into our country."

Tempers flared when Sen. Jon Kyl, R-Ariz., challenged Holder to say how a civilian trial could be the best idea, since Mohammed had previously sought to plead guilty before a military commission.

"How can you be more likely to get a conviction in a (civilian) court than that?" pressed Kyl, to applause from some in the hearing room.

The attorney general said his decision was not based "on the whims or the desires of Khalid Sheikh Mohammed. ... He will not select the prosecution venue. I will. And I have."

Critics of Holder's decision _ mostly Republicans _ have argued the trial will give Mohammed a world stage to spout hateful rhetoric.

Holder said such concerns are misplaced, because judges can control unruly defendants and any pronouncements by Mohammed would only make him look worse.

"I have every confidence that the nation and the world will see him for the coward that he is," Holder told the committee. "I'm not scared of what Khalid Sheikh Mohammed has to say at trial _ and no one else needs to be, either."

Democrats on the panel were largely supportive of the administration's decision.

"We're the most powerful nation on earth; we have a justice system that is the envy of the world. We will not be afraid," said Chairman Patrick Leahy, D-Vt.

Among the spectators were some relatives of 9/11 victims who disagree with Holder's plan to put Mohammed, the most senior al-Qaida suspect in U.S. custody, on public trial.

Opponents of the plan, including Holder's predecessor, Michael Mukasey, have accused him of adopting a "pre-9/11" approach to terrorism.

Holder emphatically denied that.

"We are at war, and we will use every instrument of national power _ civilian, military, law enforcement, intelligence, diplomatic and others _ to win," Holder said.

But South Carolina Republican Sen. Lindsey Graham called the decision "a perversion of justice" by putting wartime enemies into the civilian criminal justice system. "We're making history, and we're making bad history," Graham said.

The attorney general said he does not believe holding the trial in New York _ at a federal courthouse that has seen a number of high-profile terrorism trials in recent decades _ will increase the risk of terror attacks there.

He also voiced support for extra federal money for the city to help safeguard the area while the trials are under way.

Alice Hoagland, whose son Mark Bingham died aboard Flight 93, spoke with Holder after the hearing had ended. One of four jetliners hijacked on 9/11, Flight 93 crashed into a Pennsylvania field after passengers rushed the cabin.

"We are heartsick and weary of the delays and machinations," said Hoagland, of Redwood Estates, Calif.

Holder sought to reassure her there was evidence, not yet made public, that makes federal court the best place to try Mohammed.

"I guess what I'm saying is trust me," the attorney general said quietly, as reporters and security staff crowded around the pair.

"I will trust you. I will defer judgment," said Hoagland, though she added she still has serious doubts about his plan.