Iranian President Hassan Rouhani has defended the nuclear deal with Western powers, saying US President Donald Trump could not undermine it.
Under the 2015 deal, Iran agreed to limit its disputed nuclear programme in return for the easing of economic sanctions.
However, Mr Trump is expected to announce soon that he will decertify the deal, a senior administration official has said, in a step that potentially could cause the accord to unravel.
"In the nuclear negotiations and agreement we reached issues and benefits that are not reversible. No one can turn that back, not Mr Trump or anyone else," Mr Rouhani said on Saturday at a ceremony at Tehran University marking the start of the university academic year, according to state media.
"Even if 10 other Trumps are created in the world, these are not reversible."
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Mr Trump, who has called the pact an "embarrassment" and "the worst deal ever negotiated", has been weighing whether the deal serves US security interests as he faces the October 15 deadline for certifying that Iran is complying with its terms.
If Mr Trump does not certify that Iran is in compliance, the US Congress will have 60 days to decide whether to reimpose sanctions waived under the deal. UN inspectors have verified Iranian compliance with the terms.
Mr Rouhani said Saturday that if the United States violated the deal then it would hurt its own reputation in the international community.