Drawing of court hearing for Zacarias Moussaoui (in green)

A U.S. court has accepted a guilty plea from French terrorist Zacarias Moussaoui, the only person charged in the September 11, 2001 attacks in the United States killing nearly 3,000 people. Moussaoui told the court he was also involved in a planned attack on the White House.

The self-declared Al-Qaida operative pleaded guilty to six conspiracy charges in the attacks, ending a three-year hearing phase.

Judge Leonie Brinkema accepted the plea, despite concerns from his court-appointed lawyer that he was mentally unfit to make decisions in his own defense.

After entering his plea Friday, Moussaoui denied an actual role in the September 11 attacks, saying he was involved in a broader terrorist conspiracy to use airplanes as weapons. He said his plan was to crash a plane into the White House to press for the release of Sheik Omar Abdel Rahman, who was jailed for planning a separate attack on the World Trade Center in 1993.

The French citizen of Moroccan descent also vowed to fight the death penalty, which applies to four of the six charges in his case.

Alberto Gonzales

U.S. Attorney General Alberto Gonzales says he is happy with the outcome and says officials will work to apply the death penalty in the sentencing phase. "There a lot of people who worked for years on this case. We have achieved a successful verdict as to the first phase of the trial, but it's not over. We look forward to working on the second phase," he said.

At Friday's hearing, Moussaoui's lawyer did not challenge the plea as he had earlier this week, saying he did not understand the law and the charges against him.

Also at the trial were relatives of September 11 victims, including Debra Burlingame, who praised the work of U.S. prosecutors. "I think this is a great day for American justice. We have here an iron-clad guilty plea on six counts of conspiracy in furtherance of the September 11th plot which killed my brother and three-thousand other Americans," she said.

When the trial opened in 2002, Moussaoui had initially tried to defend himself, but the judge ordered him to accept a legal team after he filed dozens of motions criticizing the court, the judge and the U.S. government.