Democratic candidate Joe Biden warned during the final face off with President Donald Trump, before the November 3 presidential debate on Thursday, that if any country interferes in the US election it “will pay a price”.

Both Biden and Trump were responding to a question on recent reports that Russia and Iran were interfering in the elections. Director of National Intelligence John Ratcliffe had said both Iran and Russia had obtained US voter registration information in a bid to interfere in the election.

“Any interference in US elections won’t be tolerated… They are interfering in our sovereignity,” Biden said when questioned by moderator NBC News’ Kristen Welker.

The debate also saw Trump once again accusing Biden of taking money from Russia. “Joe got 3.5 million dollars from Russia, your family got it,” Trump said. Biden denied the charge adding, “Russia is wanting to make sure that I do not get elected because they know I know them.”

Trump responded by saying, “Nobody is tougher than me.”

Earlier on Wednesday, Ratcliffe, said at a press conference that Iran was responsible for the email campaign, made to look like it came from the Proud Boys. “This data can be used by foreign actors to attempt to communicate false information to registered voters that they hope will cause confusion, sow chaos and undermine your confidence in American democracy,” Ratcliffe said