The top law enforcement official overseeing the probe of Russian meddling in the 2016 election is defending the prosecution of foreign agents who may never see the inside of a U.S. courtroom.

Speaking Thursday at the Aspen Security Forum in Colorado, Deputy Attorney General Rod Rosenstein also said the Justice Department will notify the U.S. public when it identifies efforts by foreign government to target U.S. politics. Rosenstein unveiled a report identifying the major cyber threats that the U.S. faces.