Alexandria, Virginia - Taliban soldier John Walker Lindh, in his first appearance on Thursday in federal court, told a judge "Yes I do, thank you" when asked if he understood charges that he conspired to kill his fellow Americans in Afghanistan.

Lindh, wearing a green prison jumpsuit - his previous long hair and beard shorn - stood straight with his arms at his side throughout the hearing, glancing several times to prosecutors at his right as they outlined the charges against him. His attorney and several federal marshals stood behind him.

United States Magistrate W Curtis Sewell also asked Lindh whether he understood the penalties, which could include life in prison.

"Yes I do, sir," Lindh said in a quiet voice that could still be easily heard in the courtroom.

Lindh spoke a third time when the judge asked whether he understood that he would be kept in custody until a preliminary hearing, set for February 6.

"No sir, I don't have any questions," Lindh said, still standing at attention.

Heavy security surrounded Lindh's arrival at the federal courthouse here, just a few miles from the Pentagon, which was extensively damaged in the September 11 terrorist attacks. Snipers stood on the roof and armed officers ringed the building. Those entering the courtroom had to pass through a second metal detector in addition to the one at the courthouse door.

Lindh's parents, Frank Lindh and Marilyn Walker, who had met privately with their son and his attorney before the hearing, sat in the second row of the courtroom to watch the proceedings.

"John loves America. We love America," his father, Frank Lindh, said after the hearing. He said his son was innocent of the charges.

"It's been two years since I last saw my son. It was wonderful to see him this morning. My love for him is unconditional and absolute," said his mother, Marilyn Walker. "I am grateful that he has been brought home to his family, me, his home and his country."

Lindh was represented in the courtroom by four attorneys, including James Brosnahan of San Francisco, who spoke several times to the judge as the defence counsel.

Assistant US Attorney David Kelley said the government was insisting that Lindh remain in custody because of the risk that he would try to flee and because of his potential danger to the community.

Sewell, who granted the request, told Lindh: "The government has a right to ask that you be held for trial without bond. You have a right to a hearing."

Brosnahan told the judge that Lindh did not learn the precise charges against him until the day before.

Sewell then set the February 6 hearing to determine whether Lindh would continue to be held in custody.

Lindh faces four charges, according to the government's criminal complaint. Those are engaging in a conspiracy to kill Americans in Afghanistan, providing material support and resources to foreign terrorist organisations, engaging in prohibited transactions with the Taliban and providing goods and services to and for the benefit of the Taliban.

Outside the courthouse, US Attorney Paul McNulty said Lindh was being provided the full rights of any defendant in federal court, including the right to counsel.

"He has very competent counsel and we will work through the issues in due course," McNulty said.

Lindh was captured in November in Afghanistan after an uprising by Taliban and al-Qaida prisoners. Two years after leaving his country for Yemen to study Arabic and Islam, he was brought under tight secrecy and security to the same jail in Northern Virginia where the only man charged so far in the September 11 attacks, Zacarias Moussaoui, awaits trial on conspiracy charges.

The government's case against Lindh is built around a criminal complaint based mainly on his interviews with the FBI on December 9 and 10 and statements he made in a television interview. - Sapa-AP