The conflict between the US and Iran is a “fight to the death”, the former US national security council spokesman said.

John Ullyot, an adviser to the White House during Donald Trump’s first term, told The Telegraph that both sides were now “way past” negotiations.

“There’s no more negotiations. This is clear they are all in,” he said. “This is a fight to the death for the Iranians.”

After weeks of US military build up in the region, Mr Ullyot said it was likely that Mr Trump “made the decision only in the last 48 hours” to launch a bombing raid on targets across Iran.

He added: “He gets everything in place and then boom, he makes the call. It’s not just sending a signal; they are serious about trying to kill the Ayatollah, the head of the IRGC and others.”

He added that this was a “once-in-50-year opportunity to decapitate the regime”.