US President Joe Biden described Russian President Vladimir Putin as a "murderer," stressing that he would pay the price for his interference in the US elections.

American intelligence accused the Iranian authorities of trying to interfere in the US presidential elections, as commissioned by Supreme Leader Ali Khamenei, with the aim of preventing Donald Trump's re-election.

The report, published by the Office of the US Director of National Intelligence on Tuesday, said that Iran had launched a "multi-faceted covert campaign" aimed at "undermining" Trump's chances for re-election, as well as "undermining" community confidence in the electoral process and American institutions.

The intelligence considered that Iran was seeking, through its actions, to "sow discord and inflame social tensions" in the United States.