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.Pakistan, a key mediator, also said the deal was expected to be finalised within 24 hours and they were "preparing for the electronic signing".Before Trump's comments, Iranian foreign ministry spokesman Esmaeil 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."In a post on Truth Social, 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 weapon. 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!"