"We will not be the first to violate the accord, but they should definitely know that they will regret it if they violate it", Rouhani said in a conference in Tehran marking National Nuclear Technology Day. USA sanctions will resume unless Trump issues new "waivers" to suspend them on May 12.
Trump has repeatedly threatened to rip up the Iran nuclear agreement, a deal signed under predecessor Barack Obama.
Nuclear expert Mark Dubowitz believes that these threats expose massive flaws in the Iran deal that the Trump administration wants to address. However, "our response will be stronger than what they imagine, and they will receive it (the response) within a week", he said.
"(But) the foundations of the JCPOA (nuclear deal) have been so strong that during these 15 months of pressure. the structure has remained solid".
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Belgium, who are playing without world No 10 David Goffin, do not have a player ranked in the top 100 in their line-up. Croatia will take on the United States in the other semi-final, with both ties to be played on 14-16 September.
On Sunday, Ali Akbar Salehi, the head of Iran's Atomic Energy Organization, told that state-run press that Iran has the power to begin enriching uranium - needed to create nuclear weapons - to 20% within just four days of the Supreme Leader Ali Khamenei giving the order.
On Monday, Iran unveiled "84 achievements" in the field of nuclear technology including "a nuclear battery and centrifuges for the oil industry, nuclear fission, nuclear medicine and power plants".
Rouhani said on Monday that Iran's missile capabilities were purely defensive. His threats reveal what many deal skeptics have long argued: "unless the JCPOA is fixed, Iran has pathways to dozens of nuclear-tipped missiles capable of striking USA forces, United States allies, and eventually the U.S. homeland".
"We will produce any weapons necessary to defend our country in such a volatile region".
Without mentioning the USA, he said other parties to the deal are "instigating Iran" to break its commitment to the agreement. A dollar was 36,000 rials in mid-September.