Trump says US-Iran deal to be signed on Sunday as Tehran casts doubt on timing

President Donald Trump has said a deal to end fighting between the US and Iran is scheduled to be signed on Sunday, after Iran cast doubt on the timing.

In a post on social media, Trump said the Strait of Hormuz, a key shipping route, would be "open to all" once the deal is agreed.

On Saturday, Pakistan, a key mediator, also said the deal was "likely expected" to be finalised within 24 hours and they were "preparing for the electronic signing".

Before Trump's comments, Iranian foreign ministry spokesman Esmail Baghaei expressed caution over the timeline, saying: "We will have to wait and see about the exact date of the signing of the memorandum of understanding, although it will not be tomorrow [Sunday]."

A delegation from Qatar, which has also mediated in the talks, arrived in Tehran on Sunday, Iranian media reported.

It was not clear if the visit would affect the timing of Iran's expected signature of the deal.

In a post on Truth Social on Saturday, Trump wrote: "The Deal is scheduled to get signed tomorrow, and immediately after it is signed, the Hormuz Strait is OPEN TO ALL."

In an apparent reference to Iran's enriched uranium stockpiles, Trump said that "at the appropriate time, when all is calm, we will go in and get the Nuclear Dust", adding it would later be destroyed.

For decades, Iran has been accused by Western countries of trying to build a nuclear bomb. It has denied the accusations saying its programme is for peaceful purposes - to generate electricity and for research purposes.

Trump also warned that if things would not "work out quickly, easily and smoothly", Washington had "the ultimate alternative, hopefully never to be used again!"

Earlier on Saturday, Pakistani Prime Minister Shehbaz Sharif said that "we are closer to a peace deal than ever before".

"With finalisation likely expected in the next 24 hours, Pakistan is preparing for the electronic signing of the peace deal immediately after, followed by technical level talks next week," Sharif wrote on X.

On Friday, Iran's Foreign Minister Seyed Abbas Araghchi said that a deal with the US was close.

The agreement envisaged an end to the conflict between Israel and Hezbollah in Lebanon, he said.

Talks on Iran's nuclear programme would begin later.

US officials have confirmed some of the details of the agreement, saying economic benefits for Iran would depend on Tehran meeting its obligations.

In recent months, variations of an agreement have been expected several times but have not been completed in the later stages.

The war began with US and Israeli strikes across Iran on 28 February, prompting Iran to attack Israel and US-allied states in the Gulf - as well as effectively closing the Strait of Hormuz, a key shipping route for the world's oil and liquefied natural gas.

Despite having agreed a ceasefire in April, the US and Iran have exchanged intermittent fire.

Previous reports from the US had suggested that the conflict between Israel and the Iran-backed Hezbollah Lebanon may not be part of this deal - with Iran reportedly insisting on it.

Israel is not part of the US-Iran deal and has also insisted it will continue striking Hezbollah, in response to its attacks in northern Israel.

Trump has typically been an ardent proponent of Israel during both his terms in the White House - but his attempts to extricate himself from a potentially drawn-out and increasingly costly conflict in the Middle East have been frustrated by Israel's ongoing operation in Lebanon.

On Sunday, Israel carried out an air strike on the southern suburbs of Beirut known as Dahieh, a Hezbollah stronghold in the Lebanese capital.

Pictures posted online show a large plume of smoke where the location was hit.

Israel confirmed it carried out the attack, saying it was in response to Hezbollah's firing into Israeli territory.

Trump has previously stopped Israel from carrying out attacks in Beirut.

Earlier this month, Israel bombed sites in Iran for the first time since a ceasefire in April, after Iran fired missiles at Israel, in what Tehran said was retaliation for Israeli strikes on Lebanon's capital.

It is not clear if the Israeli strikes will have any impact on Iran's plans to sign the deal with the US.