Ayatollah Ali Khamenei has called for a direct attack on US interests in revenge for the death of Qassem Soleimani while the head of Iran's revolutionary guard vowed to 'set ablaze' American allies.
Khamenei has ordered Iranian forces to carry out a direct retaliation rather than relying on Tehran's proxies in the region.
The supreme leader, who wept in public over Soleimani's coffin in Tehran yesterday, has vowed 'severe revenge' for the drone strike which killed the general.
Meanwhile the revolutionary guard chief Hossein Salami told mourners at Soleimani's funeral today that Iran would hit places supported by Washington.
Salami made the pledge before a crowd of thousands gathered in a central square in Kerman, where a deadly stampede later broke out.
'The martyr Qassem Soleimani is more powerful... now that he is dead,' the revolutionary guards leader told mourners today.
'The enemy killed him unjustly. We will take revenge. We will set ablaze where they like,' Salami said, drawing cries of 'Death to Israel!'
Tehran says it has worked up 13 sets of plans for revenge for Soleimani's killing, but has not provided details.
Ali Shamkhani, the secretary of Iran's Supreme National Security Council, said that even the weakest among them would be a 'historic nightmare' for the U.S.
'If the U.S. troops do not leave our region voluntarily and upright, we will do something to carry their bodies horizontally out,' Shamkhani said.
American forces are braced for retaliation and the US-led coalition against ISIS said in a statement that it was pausing its fight against the jihadists to shore up its own defences.