Osama bin Laden's son-in-law and former spokesman pleaded not guilty Friday to terrorism charges in New York, where he was brought a week ago after a top secret US operation.
Sulaiman Abu Ghaith, reportedly a 47-year-old Kuwaiti and allegedly a senior propagandist in the Al-Qaeda network, is accused of conspiring "to kill nationals of the United States."
He faces a maximum penalty of life in prison if found guilty.
Judge Lewis Kaplan, presiding over Manhattan's grandest ceremonial courtroom, remanded Abu Ghaith in custody until an April 8 hearing at which a trial date is expected to be set.
Abu Ghaith, balding and with a short grey beard, wore a dark blue prison smock and was handcuffed in his first public appearance since being spirited to US soil.
Security was visibly heavy, with a beefed up presence of marshals and a bomb sniffing dog in and around the courtroom.
Amid mystery about the circumstances of his arrest, one of Abu Ghaith's court-appointed defense lawyers said he was detained "by United States law enforcement" overseas on February 28, then was brought to New York on March 1.
The arraignment took place just a few blocks from the site of the World Trade Center, where the Twin Towers were destroyed on September 11, 2001 by airliners hijacked by Al-Qaeda militants.
The proximity of Ground Zero to Abu Ghaith's upcoming trial was already raising political tensions.
In 2010, the government scrapped a plan to put five Qaeda figures on trial in the same court for plotting the 9/11 attacks, after bitter recriminations from some families of those killed in the World Trade Center.
There was also concerted opposition from New York officials, who described the prospect of the trials as a security nightmare. Eventually, the five were sent to the controversial prison at Guantanamo Bay.
The dispute about terrorism trials in New York is also bound up with President Barack Obama's failure to make good on a promise to close Guantanamo, and Republican pressure to prevent such a move.
Senator John Cornyn, a Republican from Texas, lashed out at the White House on Friday, saying Congress should have been told about the surprise arrival of Abu Ghaith. He insisted that Guantanamo is "the only place where we should be detaining America's most dangerous enemy combatants -- period."
However, Abu Ghaith's appearance in a civilian court was welcomed by Daphne Eviatar of Human Rights First.
"Today's efficient arraignment is a far cry from the clumsy military commissions proceedings we see at Guantanamo, she said in a statement.
"Today's hearing took 17 minutes, the government had already turned over the bulk of its unclassified discovery and the judge announced that he will set a trial date next month."
By contrast, 13 hours were needed for the initial processing of the alleged 9/11 plotters when they got to Guantanamo and no trial date has been set.
"The prosecution of Sulaiman Abu Ghaith clearly demonstrates that federal courts are the best venue for federal terrorism trials," she said.
Attorney General Eric Holder said Thursday that the arrest showed that the United States would not give up on tracking down Al-Qaeda members.
"No amount of distance or time will weaken our resolve to bring America's enemies to justice," Holder said.
"There is no corner of the world where you can escape from justice because we will do everything in our power to hold you accountable to the fullest extent of the law."