New York: US authorities have charged two Iranians with conspiring to carry out terror attacks in the country and participating in a plot, allegedly directed by elements of the Iranian government, to assassinate the Saudi Ambassador to the United States.

A criminal complaint filed on Wednesday in the Southern District of New York charges Manssor Arbabsiar, a 56-year-old naturalised US citizen holding both Iranian and US passports, and Gholam Shakuri, an Iran-based member of Iran's Qods Force, a special operations unit of the Iranian Islamic Revolutionary Guard Corps (IRGC) that is said to sponsor and promote terrorist activities abroad.

The charges against the two include conspiracy to murder a foreign official, conspiracy to use a weapon of mass destruction and conspiracy to commit an act of international terrorism transcending national boundaries.

Arbabsiar is further charged with an additional count of foreign travel and use of interstate and foreign commerce facilities in the commission of murder-for-hire. While Shakuri remains at large, Arbabsiar was arrested on September 29 at New York's John F Kennedy International Airport.

He will make his initial appearance on Wednesday before the federal court in Manhattan and faces a maximum potential sentence of life in prison if convicted of all the charges.

"The criminal complaint unsealed today exposes a deadly plot directed by factions of the Iranian government to assassinate a foreign Ambassador on US soil with explosives," Attorney General Eric Holder said, announcing the charges.

The criminal complaint alleges that Arbabsiar and his Iran-based co-conspirators, including Shakuri began plotting the murder of the Saudi Ambassador early this year.