Iran has raised the stakes in its row with the US over the alleged plot to kill the Saudi ambassador to Washington by demanding an official apology from the Obama administration over the claim that Tehran was responsible.
The Swiss embassy in Tehran, which hosts the US interests section in the Islamic republic, passed a letter from the Iranian government to US officials on Friday outlining Iran's formal complaint over accusations that military factions inside the regime were directly linked to the alleged plot.
"In a recent letter to the US government, Iran has insisted that American authorities must publicly apologise to the Iranian government and its citizens for the false accusations they publicised against Tehran in violation of international norms and regulations," Iran's state-run Press TV reported.
US officials claimed to have uncovered an Iranian plot to assassinate Adel al-Jubeir in a sting operation involving the FBI and the Drug Enforcement Administration.
The US said Iran was attempting to hire a member of a Mexican drug cartel to carry out the killing but failed because the gang member was actually a US informant.