Speaking to reporters at the White House, Trump said the talks were taking place at the request of Iran as well as regional countries, including Saudi Arabia, the United Arab Emirates and Qatar.

“Talks are going on right now,” Trump said. “This is a last chance for them to sign a good document.”

Trump warned that Iran faced “decapitation” if it failed to reach an agreement, reiterating his threat to launch a major attack on the country.

“I think we’re going to maybe get something, but I want to give them every last chance before decapitation,” he said.

Earlier in the day, after Iran said no negotiations were under way, Trump criticised what he called the country’s “unbelievably duplicitous” leadership.