US diplomatic moves come in concert with prosecutors charging two in connection with a plot to murder Adel Al Jubair, Saudi Arabia's ambassador to the United States, linking Iran to the alleged murder plot in court documents.
Officials in Washington urged the world to take concerted action against Tehran for an alleged plot to assassinate the Saudi ambassador in Washington as the kingdom's foreign minister accused Tehran of "murder and mayhem''.
As US diplomats began consultations behind closed doors at the United Nations, Secretary of State Hillary Clinton rallied support for tough new measures against Iran.
In London, Foreign Secretary William Hague told lawmakers Britain was working with the US, Saudi Arabia and others to agree on a tough international response to the plan to assassinate the envoy.
The US Treasury's top official fighting financing of terrorism said that Washington was considering additional sanctions on Iran's central bank.
Meanwhile, the Treasury department slapped sanctions on Mahan Air, a Tehran-based commercial airline accused of ferrying around the Middle East members of Iran's Islamic Revolutionary Guards Corps implicated in the plot.
In Vienna, Saudi Foreign Minister Prince Saud Al Faisal said: "We will not bow to such a pressure." He also said "we hold them accountable for any action they take against us."
Iran has urged Saudi Arabia "not to fall into the trap" of believing US claims, which it says "serve only the US and Israel."
But regional analysts say it is unlikely Riyadh will be moved by Tehran's rhetoric noting mounting tensions between Saudi Arabia and Iran over in what Saudi officials see as clear moves by the Islamic Republic to agitate Shiite communities as a means of destabilizing Sunni monarchies.
Saudi Arabia and its Gulf allies have increasingly focused their efforts on countering Iranian influence in the region.