"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, " said US Attorney General Holder in a statement.

BBC: Extradited 'arms dealer' Viktor Bout arrives in US

The decision of an appeals court in Thailand to extradite suspected Russian arms trafficker Viktor Bout to the U.S. is a big and important victory for U.S. law enforcement, particularly the Justice Department and the Drug Enforcement Administration.

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"Contrary to two rulings by a Thai criminal court which concluded that Viktor Bout's guilt was not proven, he has still - by a decision of the Thai government - been extradited to the United States, " Mr Lavrov told Rossiya TV on Tuesday.

BBC: Extradited 'arms dealer' Viktor Bout arrives in US