U.S. Drug Enforcement Administration agents accompanied Monzer al-Kassar on a private flight from Madrid that arrived in New York on Friday. He was to be arraigned in federal court in Manhattan.
Al-Kassar, who was born in Syria and is a longtime resident of Spain, was arrested in Madrid in June 2007 as part of a U.S. sting operation. An indictment accuses him of conspiring to support terrorists, conspiring to kill U.S. soldiers, conspiring to acquire and use anti-aircraft missiles, and money laundering.
Al-Kassar "intended to provide millions of dollars worth of legal weapons to a foreign terrorist organization to be used to kill Americans," U.S. Attorney Michael Garcia said in a statement.
Garcia said al-Kassar was brought to justice "as a result of extraordinary cooperation with our international law enforcement partners."
Spain's National Court approved the extradition in October, and after al-Kassar lost a series of appeals, the Spanish government gave final approval last week.
As a condition for extradition, the United States agreed not to seek the death penalty or life imprisonment without parole, because Spanish law does not allow for either of those forms of punishment, said William Ostick, spokesman for the U.S. embassy in Spain.
In his appeal, al-Kassar argued that the charges against him were of dubious legality, and that the United States had racist and political motives in pursuing him.
But in rejecting the appeal, a panel of National Court judges said that he had been a known arms trafficker since the 1970s and had provided weapons to armed groups in countries including Nicaragua, Brazil, Bosnia, Iran and Iraq.
The United States says that in the sting operation, undercover officers of the DEA arranged a fictitious deal with al-Kassar, convincing him they represented rebels of the Revolutionary Armed Forces of Colombia, or FARC.
They said they wanted to buy surface-to-air missile systems, rocket-propelled grenade launchers, thousands of machine guns and millions of rounds of ammunition for the group to take down U.S. helicopters aiding Colombia's battle against drug traffickers.
According to the indictment obtained by CBS News, al-Kassar "developed an international network of criminal associates, front companies, and bank accounts in, among other countries, the United Kingdon, Spain, Lebanon, Syria, Iraq, Poland, Bulgaria and Romania."
The indictment further alleges al-Kassar "has engaged in money-laundering transactions in bank accounts throughout the world to disguise the illicit nature of his criminal proceeds."
Al-Kassar has lived in the jet-set resort of Marbella on Spain's Costa del Sol for many years.
He stood trial in Spain in 1995 on charges of supplying assault rifles used by Palestinian militants in the hijacking of the Italian cruise ship Achille Lauro in 1985, in which one American was killed. He was acquitted for lack of evidence.
U.S. authorities did not have the name of al-Kassar's lawyer.