Trump says Iran's nuclear ban to be formalised

US President Donald Trump has said Iran will never possess nuclear weapons and that the country's inability to obtain them will soon be formally enshrined in an agreement.

Speaking in an interview with Fox News, Trump also warned that the Strait would "be open very soon" or Iran would face severe consequences.

"If you look at what's happening, Iran, as an example, will never have a nuclear weapon. They already can't, but it's going to be formal," he said.

According to Trump, the Strait is going to be open very soon or "they are going to get hit very hard and the Strait's going to be open."

"We were going to a tremendous attack. Biggest since World War II," Trump said.