The preacher, Abu Hamza al-Masri, was taken to a lockup next to the federal courthouse in lower Manhattan to face charges that he conspired with Seattle men to set up a terrorist training camp in Oregon and that he helped abduct 16 hostages, two of them American tourists, in Yemen in 1998.
Just hours after their arrival in America, Syed Talha Ahsan, 33, and Babar Ahmad, 38, pleaded not guilty in federal court in New Haven, Conn., to charges that they provided terrorists in Afghanistan and Chechnya with cash, recruits and equipment.
Ahmad made efforts to secure GPS devices, Kevlar helmets, night vision goggles, ballistic vests and camouflage uniforms, prosecutors said.
They were kept detained while they await trial in Connecticut, where an Internet service provider was allegedly used to host a website. Their lawyers declined to comment.
Al-Masri, a one-time nightclub bouncer, will be housed in Manhattan along with Khaled al-Fawwaz, 50, a citizen of Saudi Arabia, and Adel Abdul Bary, 52, an Egyptian citizen, who will face trial on charges that they participated in the bombings of two U.S. embassies in Africa in 1998. The attacks killed 224 people, including 12 Americans. They were indicted in a case that also charged Osama bin Laden.
Al-Masri, al-Fawwaz and Bary were scheduled to make an initial appearance Saturday in federal court in Manhattan.
U.S. Attorney Preet Bharara called the extraditions "a watershed moment in our nation's efforts to eradicate terrorism."
He added: "As is charged, these are men who were at the nerve centers of Al Qaeda's acts of terror, and they caused blood to be shed, lives to be lost, and families to be shattered."
In the 1990s, al-Masri turned London's Finsbury Park Mosque into a training ground for extremist Islamists, attracting men including Sept. 11 conspirator Zacarias Moussaoui and "shoe bomber" Richard Reid.
Al-Masri is not the first ailing Egyptian-born preacher to be brought to Manhattan for trial. A blind sheik, Omar Abdel-Rahman, is serving a life sentence after he was convicted in 1995 in a plot to assassinate then-Egyptian President Hosni Mubarak and in another to blow up New York landmarks, including the United Nations and two tunnels and a bridge linking New Jersey to Manhattan. Abdel-Rahman has numerous health issues, including heart trouble.
In England, lawyers for the 54-year-old al-Masri, who has one eye and hooks in place of hands he claims to have lost fighting the Soviets in Afghanistan, said he suffers from depression, chronic sleep deprivation, diabetes and other ailments.
The overnight trip to the United States came after a multi-year extradition fight that ended Friday, when Britain's High Court ruled that the men had no more grounds for appeal and could be sent to the U.S. immediately. The men have been battling extradition for between eight and 14 years.
"I'm absolutely delighted that Abu Hamza is now out of this country," British Prime Minister David Cameron said. "Like the rest of the public I'm sick to the back teeth of people who come here, threaten our country, who stay at vast expense to the taxpayer and we can't get rid of them."
"I'm delighted on this occasion we've managed to send this person off to a country where he will face justice," he added.
Al-Masri has been in a British jail since 2004 on separate charges of inciting racial hatred and encouraging followers to kill non-Muslims.
While al-Masri has been portrayed in the British media as one of the most dangerous men in the country, the case against Ahmad in Connecticut has raised concerns among legal experts and human rights advocates.
Some lawyers and lawmakers have expressed concerns because Britain agreed to extradite him even though his alleged crimes were committed in Britain and British courts declined to prosecute him for lack of evidence. Ahmad and Ahsan are accused of running websites to support Afghanistan's ousted Taliban regime, Chechen rebels and associated terrorist groups.
In prison since 2004, Ahmad, a London computer expert, has been held without charge for the longest period of any British citizen detained since the Sept. 11 attacks.
In a statement read on his behalf outside court in London Friday, Ahmad said his case had exposed flaws in U.S.-U.K. extradition arrangements. "I leave with my head held high, having won the moral victory," he said.
His father, Ashfaq Ahmad, said he would continue to fight for his son.
"It's not just one Babar Ahmad. Tomorrow there will be another Babar Ahmad and another one," he said.