TEHRAN - An adviser to Iran's supreme leader warned on Monday that if the United States or Israel were to attack Iran under the pretext of nuclear concerns, the country would be compelled to pursue the development of nuclear weapons, according to the official news agency IRNA.

Ali Larijani, an adviser to Iran's Supreme Leader Ali Khamenei, made the remarks in response to recent anti-Tehran threats made by US President Donald Trump and Israel.

Larijani noted that Iran had been prohibited from acquiring nuclear weapons under a religious directive issued by Khamenei. However, he added, "If the United States makes any mistake, Iran will be forced to pursue nuclear weapons due to pressure from its people".

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Larijani stressed that taking military actions against Iran would have consequences, saying Iran's nuclear program would not be destroyed through bombing.

Larijani said any potential indirect negotiation with the United States would be aimed at understanding each other's demands and winning mutual concessions regarding the nuclear issue.

Also on Monday, Iran's Foreign Ministry summoned Switzerland's envoy to Tehran to protest the Trump’s comments, calling his remarks a violation of international law.

Ministry spokesman Esmaeil Baghaei, in a post on social media platform X, denounced Trump's statements as "a shocking affront to the very essence of international peace and security" and accused the US leader of breaching the United Nations Charter and undermining safeguards under the International Atomic Energy Agency (IAEA).

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The Swiss envoy, representing US interests in Iran, was handed an official protest during a meeting with Iranian officials. Tehran warned it would respond "decisively and promptly" to any aggression, according to a ministry statement.

Trump, in an interview with NBC News on Sunday, threatened to launch "unprecedented military strikes" on Iran if it refused to negotiate over its nuclear program.

"If they don't make a deal, there will be bombing like they've never seen before," he said, claiming US and Iranian officials are "talking", without offering details.

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The remarks followed a letter Trump sent to Iranian leaders in early March via the United Arab Emirates, proposing direct negotiations on Tehran's nuclear activities.

Iranian President Masoud Pezeshkian confirmed on Sunday that Tehran had rejected the proposed face-to-face talks but left open the possibility of indirect talks.

He stressed that while Iran is not against negotiations in principle, Washington must first rectify its past "misconduct" and rebuild trust.