Araghchi says Iran-US final deal talks will not begin if threats from Washington continue.
Iran cites the MoU as Trump warns Tehran over nuclear ambitions and possible military action.
Tensions rise in the Gulf as diplomatic efforts remain under pressure.
Iran has said negotiations on a final agreement with the United States will not begin if Washington continues to issue threats, with Foreign Minister Seyed Abbas Araghchi warning that such statements would violate the terms of an interim memorandum of understanding (MoU) signed between the two countries last month.
Araghchi's remarks followed US President Donald Trump's warning that Washington would either secure a deal with Tehran or "finish the job" if diplomacy failed. The exchange has added pressure to the diplomatic process launched under the Pakistan-brokered MoU, which calls for indirect talks between Iran and the US while committing both sides to refrain from the threat or use of force against each other.
In a post on X on Tuesday, Araghchi cited Paragraph 13 of the agreement, writing, "Para 13 of the MoU is clear: Negotiations on final Deal will not commence if threats continue. Honor your signature."
He also wrote, "Millions of proud Iranians rallied in unity to honor Grand Ayatollah Khamenei and his legacy. Neither them nor our Brave Armed Forces are moved by any threats."
The Islamabad memorandum of understanding, brokered by Pakistan, entered into force on June 18 after Iranian President Masoud Pezeshkian and Trump signed it electronically. The 14-point agreement established a 60-day period of diplomacy through indirect talks between Tehran and Washington aimed at reaching a lasting peace deal.
Trump, speaking at the White House, said the US was prepared to use military force if diplomacy failed and reiterated that Iran would not be allowed to possess nuclear weapons.
"We're going to win one way or the other. We're going to either make a deal or we're going to finish the job—and it won't be tough to finish the job," Trump said, while adding that he would prefer a diplomatic resolution.
"I'd rather make a deal because I don't want to affect 91 million people. We can knock down their bridges in one hour," he said.
Trump also said the US would get the "nuclear dust" and insisted that Iran would not be allowed to possess nuclear weapons.
Araghchi's comments came as Iran observed a days-long mourning period following the funeral of its Supreme Leader, Ayatollah Ali Khamenei. Araghchi shared photographs showing large crowds gathered in Tehran for Khamenei's funeral procession.
The remarks also followed a statement from Israeli Defence Minister Israel Katz, who said Israel would "thwart" any future Iranian leader who sought to attack the country.
Meanwhile, tensions remained high in the Gulf. On Monday, an oil tanker caught fire after being struck by an "unknown projectile" off the coast of Oman near the Strait of Hormuz. According to the United Kingdom Maritime Trade Operations (UKMTO), the incident took place about eight nautical miles east of Limah, Oman, along one of the world's busiest energy shipping routes.
Axios, citing two US officials, reported that Iran's Revolutionary Guards fired at least two missiles at commercial vessels transiting the Strait of Hormuz on Monday night. The report said two commercial ships sustained significant damage, although no casualties were reported.
(With inputs from Anadolu Agency)
