The UK's Foreign Office has also temporarily closed the British embassy in Tehran, which will now operate remotely, a government spokesperson said.

Trump had earlier threatened "very strong action" against Iran if the government executed protesters, after reports emerged that a 26-year-old man who had been arrested during the height of the demonstrations had been sentenced to death.

Erfan Soltani was scheduled to be executed on Wednesday, his family had told BBC Persian. They later told the Norway-based Kurdish human rights group Hengaw that his execution had been postponed.

On Thursday, Iranian state media said Soltani was arrested during the protests but denied he was sentenced to death.

Speaking from the White House, Trump said his administration had been told "on good authority" that "the killing in Iran is stopping, and there's no plan for executions".

When questioned by a reporter, Trump said that "very important sources on the other side" had informed him of the developments, adding that he hoped the reports were true.

Iranian authorities have reportedly failed to give Soltani's family any more information about his case, citing only that he had been arrested in connection with a protest.

The clothes shop owner was detained in the city of Fardis, just west of Tehran, last week.

Responding to reports of potential executions, Iran's Foreign Minister Abbas Araghchi said "hanging is out of the question" and there would be "no hanging today or tomorrow".

Speaking to Fox News, he also warned the US president to "not repeat the same mistake that you did in June," adding: "If you try a failed experience, you will get the same result." In June 2025, the US bombed three of Iran's nuclear sites over fears Tehran could use them to build a nuclear weapon.

Initial demonstrations over the collapse of the Iranian currency began in late December, but swiftly expanded into a wider crisis of legitimacy for Iran's clerical leadership.

In addition to the temporary closure of the British embassy in Tehran, the US Mission to Saudi Arabia has advised its personnel and citizens to "exercise increased caution and limit non-essential travel to any military installations in the region".

Italy and Poland have published statements urging their citizens to leave Iran, while Germany has issued a notice to air operators recommending that flights do not enter Iranian airspace, citing potential risk from "escalating conflict and anti-aviation weaponry".

German airline Lufthansa issued a statement confirming its flights would avoid Iranian and Iraqi airspace "until further notice".

The US embassy in Doha has advised its personnel to exercise increased caution and limit non-essential travel to the Al-Udeid air base, while the Qatari government said it would continue to "implement all necessary measures to safeguard the security and safety of its citizens and residents".

Al-Udeid is the largest US military base in the Middle East with about 10,000 personnel based there, as well as around 100 UK staff. It is not clear how many will be leaving.

Earlier this week, the US president had urged Iranians to "KEEP PROTESTING" via a post on his Truth Social platform, promising that "HELP IS ON ITS WAY".

Trump has been reluctant to lend his support to any challengers to Iran's Supreme Leader, Ayatollah Ali Khamenei, saying that "we aren't really up to that point yet" in an interview with Reuters on Wednesday.

When asked whether he could support Iranian opposition figure Reza Pahlavi, the exiled son of Iran's last shah, Trump said "I don't know whether or not his country would accept his leadership, and certainly if they would, that would be fine with me".

"He seems very nice, but I don't know how he'd play within his own country," Trump added.

Many Iranian demonstrators called for Pahlavi's return during the protests which began more than three weeks ago, but it is difficult to establish the extent of his backing within the country.

Trump also said that the Iranian government could fall due to the protests, but added that "any regime can fail".

Tehran has imposed an internet blackout on the country since last Thursday, as authorities stepped up their crackdown on anti-government demonstrations.

The BBC and most other international news organisations are also unable to report from inside Iran, making obtaining and verifying information difficult.

The US-based Human Rights Activists News Agency (HRANA) said it had so far confirmed the killing of 2,435 protesters, as well as 13 children. The group said a further 882 deaths remain under investigation.