A former Canadian Armed Forces reservist from Manitoba has been sentenced to nine years in prison in a case that highlighted a U.S. federal crackdown on far-right extremists.

Twenty-eight-year-old Patrik Mathews of Beausejour told U.S. District Court Judge Theodore Chuang before sentencing that his connection to a white supremacist group was a colossal failure of judgment.

But Chuang noted that Mathews never apologized for his role in what the FBI says was a violent plot to trigger a "race war" in the United States.

The judge also said recorded conversations between Mathews and another man who pleaded guilty in the case captured "passion" in their willingness to kill people and bring down the U.S. government.