Speaking to reporters upon his arrival in Pennsylvania, where he visited the Mack Trucks facility in Lehigh County, Trump dismissed concerns over Iran's stance on inspections.

Responding to questions on UN nuclear watchdog inspectors would be deployed under the agreement, Trump insisted that Iran had already agreed in principle.

"They're wrong. They're wrong. They're wrong. They know they're wrong. They told us inside and we have it down 100 per cent for inspections. And if they were right, I'd cancel the meetings right now," Trump said.

When asked about the timeline for inspections, he added, "At the appropriate time. There's no rush, but they'll be on the ground at the appropriate time."

He further claimed that negotiations with Iran were progressing and suggested that Tehran's position had been significantly weakened.