Iran is considering 13 'revenge scenarios' in retaliation for the US airstrike that killed General Qassem Soleimani in Iraq, a top official has said.
Ali Shamkhani, secretary of Iran's Supreme National Security Council, vowed that even if Tehran opted for the weakest option, it will create an 'historic nightmare for the Americans'.
Iran has vowed to exact a 'crushing revenge' over the killing of Soleimani, which is expected to ramp up Tuesday after a three-day period of mourning ends.
The country has already ripped up what remained of the nuclear deal signed under Obama in the wake of the strike, and Iraq has voted to kick all US troops out.
Rockets have also been launched at the Green Zone surrounding the US embassy in Baghdad, with the area expected to come under increasing attacks.
Some 5,000 US troops stationed across Iraq and 500 still in Syria are also expected to be targeted in response.
Hassan Nasrallah, the Lebanese secretary-general of Iran-backed Hezbollah, said all US bases, all warships and every single soldier in the region is now a target.
'The true, just retribution for those who conducted this assassination is an institution, which is the U.S. military,' he said during a ceremony to mourn Soleimani's death in Beirut on Sunday.
'We will launch a battle against those killers, those criminals.'
US intelligence believes that Iran will try to kill one of its top generals in the region in a tit-for-tat slaying.
One official said the U.S. anticipates a 'major' attack of some type within the next day or two.
The U.S. military has increased protection of its forces, particularly in Iraq.
Iran's parliament also passed a bill on Tuesday designating all US forces 'terrorists' over the killing.
Under the newly adopted bill, all US forces and employees of the Pentagon and affiliated organisations, agents and commanders and those who ordered the 'martyrdom' of Soleimani were designated as terrorists.
'Any aid to these forces, including military, intelligence, financial, technical, service or logistical, will be considered as co-operation in a terrorist act,' the Iranian parliament said.
According to reports on social media, Iranian lawmakers chanted 'Death to America' while voting for passage of the bill.
Lawmakers also voted to bolster by £170million the coffers of the Quds Force - the foreign operations arm of Iran's Revolutionary Guards that was headed by Soleimani.
The bill was an amended version of a law adopted in April last year that declared the United States a 'state sponsor of terrorism' and its forces in the region 'terror groups'.
Iran's top security body, the Supreme National Security Council, said that blackisting came after the US designated Iran's Revolutionary Guards a 'terrorist organisation'.
This article has been adapted from its original source.
© Associated Newspapers Ltd.