The FBI has offered to brief 2020 presidential campaigns on possible counterintelligence threats in response to cybersecurity attacks and attempted infiltration by Russian nationals during the 2016 election.

The Democratic National Committee, which had emails hacked and released during the last presidential election, has scheduled training with a former intelligence officer who will brief the campaigns on how foreign adversaries target Americans and prevention and detection methods, according to CNN.

Technical staff for the Republican National Committee have already been briefed by the FBI, and the Trump campaign said it would attend a future briefing.

Russian national Maria Butina was sentenced to 18 months in prison after she pleaded guilty to attempting to infiltrate conservative American political circles and influence U.S. relations with Russia amid the 2016 election.

Special counsel Robert Mueller also detailed in his redacted report released in April how Russian nationals made repeated attempts to make contact with Trump’s campaign and others connected to the president.

Sen. Ben Sasse, R-Neb., asked Attorney General William Barr earlier this month to give more guidance on laws about campaigns’ contacts with foreign officials.

"I think it would be helpful for us to have a shared understanding as we head into the 2020 election, of what campaign operatives should well understand is beyond the pale," he said.