The US government has brought charges against an Iranian man in connection with an alleged plot to assassinate Donald Trump before he was elected the next president.

The Department of Justice on Friday unsealed an indictment against Farhad Shakeri, 51, alleging he was tasked with “providing a plan” to kill Trump.

The US government said Mr Shakeri has not been arrested and is believed to be in Iran.

In a criminal complaint filed in Manhattan court, prosecutors allege that an official in Iran’s Revolutionary Guard directed Mr Shakeri in September to devise a plan to surveil and kill Trump.

“The Justice Department has charged an asset of the Iranian regime who was tasked by the regime to direct a network of criminal associates to further Iran’s assassination plots against its targets, including President-elect Donald Trump,” US Attorney General Merrick Garland said in a statement.

The justice department added that it had charged two others also allegedly recruited to kill an American journalist who was an outspoken critic of Iran.

The other two individuals were identified by the justice department as Carlisle Rivera, also known as "Pop", 49, from Brooklyn, and Jonathon Loadholt, 36, from Staten Island.

According to prosecutors, Mr Shakeri told them that he did not intend to propose a scheme to kill Trump within the timeframe the Iranian government wanted, so officials in the Republican Guard paused the plan.

Mr Shakeri was asked to come up with a plan to kill Trump in seven days, the indictment alleges. If he was unable to do so, Mr Sakeri said Iranian Revolutionary Guard officials told him it would be easier to try to assassinate Trump after the election, because they believed he would lose, prosecutors said.