Iran’s envoy to the United Nations has said that Tehran will respond “decisively” to any “military aggression” by the United States in a letter urging the UN Security Council to condemn recent threats from President Donald Trump.

Iran’s UN ambassador Amir Saeid Iravani called on Thursday for members of the council and UN chief Antonio Guterres to act, noting in particular Trump’s recent specific threat to use an airfield located in the Indian Ocean in the Chagos Islands, in a potential attack on Iran.

“Given the volatile situation in the region and the persistent movement and build-up of military equipment and assets by the United States, such a belligerent statement by the President of the United States must not be treated as mere rhetoric,” Iravani wrote.

The Iranian envoy emphasised that his country “neither seeks tension nor war and will not initiate any war”.

But, he said that if Iran were attacked, it would consider “all bases, facilities, and assets of the hostile force” in the region as “legitimate targets”.

Trump warned on Thursday that Tehran had 10 to 15 days to make a “meaningful deal” with Washington, as he hosted dozens of leaders from around the world for the first official meeting of his newly created Board of Peace in Washington.

“So now we may have to take it a step further, or we may not,” Trump said, again alluding to his threat of military action against Tehran.

“Maybe we’re going to make a deal. You’re going to be finding out over the next probably 10 days.”

Asked later to elaborate, Trump told reporters on board Air Force One: “I would think that would be enough time, 10, 15 days, pretty much, maximum.”

Speaking earlier in Washington, Trump renewed his argument that the joint Israeli-US strikes against Iran in June of last year paved the way to the “ceasefire” in Gaza.

Trump maintained that without the US attack on Iran’s nuclear facilities, the “threat” of Iran would have prevented countries in the region from agreeing to “peace in the Middle East”.

‘Otherwise, bad things happen’: Trump

The renewed threats and tension come just days after the US and Iran held a second round of indirect talks, which were largely described in positive terms.

On Wednesday, Iran’s Foreign Minister Abbas Araghchi said the two sides made “good progress in the negotiations” in Geneva and “were able to reach broad agreement on a set of guiding principles” for an agreement.

On Thursday, Trump said his diplomatic aides Steve Witkoff and Jared Kushner have had “very good meetings” with Iran’s representatives.

“We have to make a meaningful deal. Otherwise, bad things happen,” he said.

Despite the talks, the US has continued to amass military assets in the Gulf region, including two aircraft carriers and dozens of fighter jets.

Iranian officials have expressed defiance against the US president’s constant threats.

“The Americans constantly say that they’ve sent a warship toward Iran. Of course, a warship is a dangerous piece of military hardware,” Iranian Supreme Leader Ali Khamenei wrote on X on Thursday.

“However, more dangerous than that warship is the weapon that can send that warship to the bottom of the sea.”

Tensions between Washington and Tehran have been escalating since late 2025, when Trump, while hosting Israeli Prime Minister Benjamin Netanyahu in December, promised to strike Iran again if it attempts to rebuild its nuclear or missile programmes.

Days later, antigovernment protests broke out in Iran. Trump encouraged the demonstrators to take over state institutions, promising them that “help is on the way”.

Trump appeared to step back from the brink of attacking Iran last month, saying that the country had agreed to halt the execution of dissidents under US pressure.

The two countries later renewed negotiations with the first round of talks since the June war that took place in Oman on February 6.