"There are several areas in the negotiations that... showed that they were not serious about doing a deal," one official told reporters, adding that Iran wanted to preserve its uranium enrichment capacity "so that over time they could use it for a nuclear bomb."

Another official said Iranian authorities had already begin "rebuilding" all the nuclear sites attacked in June 2025 by US strikes -- Fordo, Natanz and Isfahan.

He also accused Iran of lying about the real use of a research center in Tehran, which was allegedly disguised as a civilian facility.

One of the senior officials, who all spoke on condition of anonymity, said Iran's missile capabilities were another concern and claimed Tehran was prepared to hit American targets.

"We had analysis that basically told us, if we sat back and waited to get hit first, the amount of casualties and damage would be substantially higher than if we acted in a preemptive, defensive way to prevent those launches from occurring," the official said.

That official added that Iranian officials "consistently have refused to address ballistic missiles."

"They will not even talk about it. They won't talk about it with us. They won't talk about it with our regional partners.

"So the president, frankly, had no choice."