Kassir, a Swede of Lebanese origin, was convicted in May. He was extradited to the United States in September 2007 from Prague, where he was jailed after his arrest in 2005 during a stopover while flying from Sweden to Lebanon.
Prosecutors said in the jury trial at a federal court in Manhattan that Kassir, 43, tried to set up a "jihad" (holy war) camp in Oregon, in the northwest United States.
Kassir declared his innocence when he was charged last year, and his lawyer said his client had "a big mouth," but was not a criminal.
Prosecutors said he reached the United States in 1999 and spent a year at an Oregon ranch, imparting religious teachings at a Seattle mosque before returning to Europe, according to the prosecution.