(CNN) The federal government warned state election officials Thursday it suspects Russia may focus on voter suppression as a means to interfere in the 2020 presidential election.

The joint FBI and Department of Homeland Security document, obtained by CNN and marked For Official Use Only, is titled "Russia May Try to Discourage Voter Turnout and Suppressing Votes in 2020 US Election."

It warns of three potential ways the Russian government "might seek to covertly discourage or suppress US voters from participating in next year's election."

Russia may try to recruit Americans to protests and intimidate voters, sow discord online within political parties and try to hack voter registration sites or knock them offline, the report warns.

"We have high confidence in this assessment based reports by firms with expertise in social network analysis, open source press reporting, and observed activity of Russian-linked social media actors," the document reads.

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