U.S. authorities over the weekend turned down a Justice Ministry request to allow convicted arms dealer Viktor Bout to serve out the rest of his sentence in his homeland.
In a letter sent Saturday to Bout's American lawyer, Albert Dayan, the U.S. side cited the seriousness of the charges against Bout, complaints from U.S. law enforcement officials and the fact that Bout is awaiting an appeal against his April conviction, the BBC's Russian service reported.
The letter also referred to Bout's "criminal past," the same past that earned him the moniker "The Merchant of Death" and made him the inspiration for the 2005 movie "Lord of War."
Bout has repeatedly denied the charges against him, saying he was a legitimate businessman, while the Foreign Ministry has argued that he was convicted on unreliable evidence due to political considerations.
Commenting on the U.S. refusal to extradite Bout, Konstantin Dolgov, Russia's commissioner for human rights, democracy and rule of law, said officials in Moscow were "concerned" about the decision and would continue to press for Bout's return to Russia, according to Interfax.
Bout, who rights groups accuse of selling weapons to countries under arms embargoes as far back as the 1990s, was arrested in 2008 in a sting operation in Thailand coordinated by the U.S. Drug Enforcement Administration.
U.S. officials say Bout agreed to sell informants up to $20 million in weapons that would be used to kill American citizens.
Despite objections from Russia, Thai authorities extradited Bout to the United States in 2010, and in April a New York judge sentenced him to 25 years in prison on counts including conspiracy to kill U.S. nationals and provide material support to a designated foreign terrorist group.
Bout is serving his sentence in a prison in Marion, Illinois. Russian officials have said his prison conditions contravene international norms.