The court, in imposing a sentence on a defendant who has been found guilty of an offense described in section 1962 of this title or in title II or III of the Comprehensive Drug Abuse Prevention and Control Act of 1970 shall order, in addition to the sentence that is imposed pursuant to the provisions of section 3551, that the defendant forfeit property to the United States in accordance with the provisions of section 1963 of this title or section 413 of the Comprehensive Drug Abuse and Control Act of 1970.