As the United States and Iran opened talks in Switzerland aimed at ending their war, US President Donald Trump claimed on Sunday that he had spoken overnight with Iranian officials and recounted an expletive-filled warning he allegedly delivered to them: if the Strait of Hormuz was shut again, they "wouldn't make it back to their f*****g country."

Peace talks in Switzerland could be off to a rough start, with Tehran warning that Israel’s attacks in Lebanon must stop.

Trump’s threat came after Iran said it had closed the strait again over the continued fighting in Lebanon, a claim the US disputes.