The US Federal Bureau of Investigation has announced Iran and Russia have taken “specific actions” to influence the 2020 US election.

“First, we have confirmed that some voter registration information has been obtained by Iran, and separately, by Russia,” US Director of National Intelligence John Ratcliffe said in a special briefing on Thursday (Australian time).

“This data can be used by foreign actors to attempt to communicate false information to registered voters, that they hope will cause confusion and undermine your confidence in American democracy.”

Mr Ratcliffe said Iran was distributing video content that implies individuals could cast fraudulent ballots, as well as “spoof emails” that are “designed to intimidate voters”.

“We have already seen Iran sending spoofed emails designed to intimidate voters, incite social unrest and damage President Trump,” he said.

“These actions are desperate attempts by desperate adversaries.”

Mr Ratcliffe and FBI director Chris Wray said the US would impose costs on any foreign countries interfering in the 2020 US election.

Americans urged not to spread misinformation

He asked “every American” to make sure the interference efforts do not have the intended effect.

“If you receive an intimidating or manipulative email in your inbox, don’t be alarmed and do not spread it. This is not a partisan issue,” Mr Ratcliffe said.

Mr Wray said Americans should be confident that their vote counts.

“Early unverified claims to the contrary should be viewed with a healthy dose of scepticism,” he said,

“We encourage everyone to seek election and voting information from reliable sources.

“Namely, your state election officials, and to be thoughtful, careful, and discerning consumers of information online.”

Earlier in the day, the Washington Post reported that two US officials had connected Iran to a series of threatening emails sent to Democratic voters.

The emails, which claimed to be sent by a far-right group called the Proud Boys, told voters to change their registration and vote for Donald Trump.

“You will vote for Trump on election day or we will come after you,” they read.

The emails appeared to contain information from “voter files”, digital databases of information that are sometimes commercially available.

The emails were discovered in Florida and Alaska, though the Post reported they had reached voters in four states, including three competitive battleground regions.

-more to come