Donald Trump's latest pronouncements on Iran and the chances of a negotiated agreement have to be taken seriously, as he is after all the president of the United States. This was reported by Qazaqyia.kz citing BBC News.

At the Nato summit in Turkey, Trump called Iran "scum" and said he didn't want to deal with them. "They're scum. They're sick people. They're led by sick people. And they're vicious, violent people. If they had a nuclear weapon, they'd use it. As far as I'm concerned, it's over," he said.

But these are not his last words. He has kept up a running commentary on the war and the memorandum of understanding (MOU) being negotiated. His words have swerved through claims of victory to threats of annihilating Iranian civilisation to support for negotiations.

Later he doubled down, saying the US "will probably hit them harder again tonight". America's capacity to hit Iran is not in doubt, but it has not been able to break the will of the regime to drop any of its fundamental demands, starting with control of the Strait of Hormuz.

Buried in his latest verbal onslaught was an acceptance that the talks will continue. They have been on hold while Iran goes through funeral obsequies for its former supreme leader Ayatollah Ali Khamenei, who was killed by Israel and the US on the first day of the war on 28 February.

Asked if the exchange of strikes meant talks were over, Trump referred to his chief negotiators Steve Witkoff and Jared Kushner, saying "I don't care, they can talk. But I think they're wasting their time." Then on the Iranian regime: "They're a bunch of lying guys."

That can be read as another admission that the president, for all his bluster, does not have a better option than negotiations. With Israel, the US tried and failed to destroy the Iranian regime.

But the negotiating process is fragile. A source among the mediators described what has happened as "a setback for sure". The atmosphere is said to be "very tense".

At the heart of the latest military exchanges is the Tehran regime's determination not to return to the way things were before 28 February. The regime is determined to keep control of the Strait of Hormuz. The ability to stop shipping carrying a fifth of the world's oil and gas gives it a chokehold on the world economy.

Iran will not agree to relinquish control of the Strait of Hormuz. That is why it is prepared to risk the MOU – laden with potential sweeteners for Iran – to make the point that there is no going back.

The regime has been emboldened by the failure of the US and Israel to destroy it. The funeral rituals of the supreme leader demonstrated that the Islamic regime has a strong core of support. Domestic opposition has not gone away, but the regime's ruthless use of force to crush protests, killing thousands in January, means it is keeping a low profile.

If the escalation can be stopped, mediators believe it is possible to do a deal with Iran that will allow shipping to transit the Strait. It would have to be part of a wider agreement that unfreezes Iranian assets abroad, allows Iran to sell its oil and most critically acknowledges Iran's authority over the Strait. In return Iran would have to accept limits on enriching uranium, allow UN nuclear inspectors back in, and account for stocks of what Trump calls "nuclear dust" – uranium already enriched close to weapons-grade. But events of the last 24 hours show how hard that will be.