Iranian Foreign Minister Javad Zarif fired back at Donald Trump on Monday, calling the U.S. president's Sunday threat via Twitter unimpressive.
Most Republicans have stayed silent on Iran following Trump's all-caps tweet warning the terrorist nation against threatening the US again, but Graham came out in support of Trump for taking a tough stance.
Mr Rouhani also said: "We should respond to them with action".
"This is a moment in history".
Washington and Tehran have been trading angry threats since Sunday, when Iranian President Hassan Rouhani warned the USA "not to play with the lion's tail" and that conflict with Iran would be the "mother of all wars". Or when the U.S. Navy fired warning shots at speedy Iranian military boats.
The Mehr news agency, one of the Iranian regime's global voices, reported recently, citing Rouhani's chief of staff Mahmoud Vaezi, that Trump asked "eight times" to meet with Rouhani while the latter attended the United Nations General Assembly in NY a year ago, but was rebuffed.
In a tweet on late Sunday, Trump warned his Iranian counterpart Hassan Rouhani that if Tehran threatened the U.S. again, it would suffer "consequences the likes of which few have ever suffered before".
In early 2017 retailers including Nordstrom Inc, Sears Holdings Corp and Kmart dropped or sharply scaled back their assortment of Trump-branded products, though they typically attributed those decisions to poor sales.
He said: "The level of corruption and wealth among regime leaders shows that Iran is run by something that resembles the Mafia more than a government".
Both the tweet and the speech landed less than two weeks before the administration will begin re-imposing sanctions on Iran that had been lifted under the 2015 nuclear deal.
Sanders said on Monday that Trump has been "very clear about what he's not going to allow to take place".
But some of Iran's neighbors who are US allies clearly support putting pressure on Iran. We've been around for millennia & seen fall of empires, incl our own, which lasted more than the life of some countries.
A senior commander of Iran's Revolutionary Guard was quoted in Iranian media saying "Iran will resist pressure from the enemies" and that Trump's threats against the country amounted to "psychological warfare", Reuters reported.
The analyst added that "neither Iran, nor any other country is interested in escalating tensions in the region". "We're ready to make a deal".
The escalation in rhetoric came as the Trump administration has launched an offensive of speeches and online communications meant to foment unrest and help pressure Iran to end its nuclear program and its support of militant groups, according to US officials familiar with the matter, reported Reuters.
USA attempts to block Iranian oil exports will not be left unanswered, Foreign Ministry Spokesman Bahram Qassemi added.