Nicholas Kaiga entered the plea Thursday, standing in a Chicago federal court in orange jail garb and with his legs shackled.
He's accused of seeking to export aluminum tubes that prosecutors say are "controlled for nuclear proliferation purposes" and can be used "in the aerospace industry, among other applications."
Prosecutors added that a Malaysian company involved is a "front company" for someone "located at times in Iran." They didn't elaborate.
Kaiga lives in Brussels and London. He was arrested in June in New York. He faces multiple charges, including violating the International Emergency Economic Powers Act.
Kaiga's lawyer declined comment Thursday.
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