President Donald Trump has threatened to “annihilate” Iran if negotiations fail, saying he faces a “big decision” as he predicted no deal with Tehran would come until after the US midterm elections in November.

Addressing the UN General Assembly in New York on Tuesday, Trump defended the US-Israeli war with Iran and accused Tehran of deliberately delaying an agreement until after the US elections.

“But I have a big decision to make. Will a deal be made with Iran that lets them rebuild and create a far greater country than it ever was before?” Trump asked, before presenting the alternative: “Or do I annihilate the Islamic Republic and do it quickly?”

“Do I drive them into hell with no chance of survival and no hope of future greatness or generations?” he continued.

Trump nevertheless said he believed an agreement would be reached “right after the election.” Later in the speech, he said Washington and Tehran would “definitely get it done… one way or the other.”

Trump also called on other countries to join the US in enforcing the “complete economic isolation” of Iran until Tehran meets Washington’s conditions.

Members of the Iranian delegation walked out of the General Assembly hall, leaving only one lower-level delegate seated, as Trump defended the nearly seven-month conflict, accusing Tehran of seeking nuclear weapons, supporting terrorism and attacking commercial shipping.

Hours later, however, Trump struck a more conciliatory tone, revealing that his envoys Steve Witkoff and Jared Kushner had held a “very productive meeting” with Iranian representatives. Witkoff said mediators shuttled between the US and Iranian delegations throughout the day and completed a round of discussions that Washington hoped would prove “constructive and promising.”

Iranian state media confirmed that Foreign Minister Abbas Araghchi had met US negotiators on the sidelines of the General Assembly at Washington’s request. According to the report, Tehran used the meeting to present its conditions for reopening the Strait of Hormuz, including an end to the US naval blockade and the release of frozen Iranian assets.

Iran’s military, meanwhile, responded defiantly to Trump’s remarks, warning that further US or Israeli escalation would be met with stronger retaliatory strikes.