“I think it’s important to remember that when you’re talking about a site like Parchin, you’re talking about a conventional military site, not a nuclear site,” US State Department spokesman John Kirby said at a daily press briefing in Washington on Thursday.

“So there wouldn’t be any IAEA or other restrictions on new construction at that site were they to occur,” he added.

The US official's remarks came in response to a question about an earlier report by the International Atomic Energy Agency (IAEA) about the construction of “a small extension to an existing building” at Parchin.

"Since (our) previous report (in May), at a particular location at the Parchin site, the agency (IAEA) has continued to observe, through satellite imagery, the presence of vehicles, equipment, and probable construction materials. In addition, a small extension to an existing building appears to have been constructed," the IAEA report said in its most recent update on Iran’s nuclear program on Thursday.

Kirby's remarks mark a deviation from past claims in the US about Parchin. Iran has repeatedly denied Western allegations about nuclear activity at the site.