Viktor Bout, reputed to be a major supplier of weapons around the world, is accused of trying to sell arms to anti-American terrorists in Colombia.
"Yes, your honor," the New York Daily News quoted Bout, garbed in a brown T-shirt and black sweatpants, as telling the judge in English in response to a question about whether he understood the charges against him.
U.S. Attorney General Eric Holder, in a statement Tuesday, said Bout has been "long considered one of the world's most prolific arms traffickers."
"Viktor Bout has been indicted in the United States, but his alleged arms trafficking activity and support of armed conflicts in Africa has been a cause of concern around the world," Holder said.
The charges against Bout include conspiring to kill U.S. nationals and U.S. officers or employees, conspiring to acquire and use an anti-aircraft missile, and conspiring to provide material support or resources to a terrorist organization.
The 43-year-old Russian is in a high-security prison in New York, where he will be held pending trial, the Justice Department said.
Bout, a former military officer believed to be worth an estimated $6 billion, was arrested in Bangkok in March 2008 during a U.S. Drug Enforcement Administration sting operation.
"For more than a decade, Mr. Bout is alleged to have plied a deadly trade in surface-to-air missiles, land mines, bullets, death and destruction," Acting DEA Administrator Michele Leonhart said. "Fortunately, with his arrest, extradition, and pending prosecution in the Southern District of New York, his last alleged attempt to deal in death means that he will finally face justice."
The Russian government in a statement Tuesday called Bout's extradition to the United States "deplorable," CNN said
"It is very deplorable that the Thai government succumbed to the outside pressure and conducted the illegal extradition of Viktor Bout," Russia's Foreign Ministry said.