WASHINGTON 

US strikes on Iran were not about the regime change, Secretary of Defense Pete Hegseth said Sunday.

"This mission was not and has not been about regime change," Hegseth said at a news conference along with Chairman of the Joint Chiefs of Staff Air Force Gen. Dan Caine.

His remarks came after US President Donald Trump announced that American forces carried out “very successful” strikes on three Iranian nuclear sites in Fordo, Natanz, and Esfahan, amid growing fears of a broader conflict.

Hegseth said Trump authorized a "precision operation to neutralize the threats to our national interests posed by the Iranian nuclear program and the collective self-defense of our troops and our ally Israel."

He added that the plan to strike Iran "took months and weeks of positioning and preparation" to be ready when Trump called.

Stressing that US strikes on Iran were an "incredible and overwhelming success," Hegseth said: "We devastated the Iranian nuclear program."

"But it's worth noting the operation did not target Iranian troops or the Iranian people," he noted.

Iran's "nuclear ambitions have been obliterated," he said, adding: "The operation President Trump planned was bold, and it was brilliant, showing the world that American deterrence is back. When this president speaks, the world should listen."

Hostilities broke out on June 13 when Israel launched airstrikes on several sites across Iran, including military and nuclear facilities, prompting Tehran to launch retaliatory strikes.

'Largest B-2 operational strike in US history'

Caine, for his part, said US Central Command (CENTCOM), under the command of General Eric Kurilla, executed last night "Operation Midnight Hammer, a deliberate and precise strike against three Iranian nuclear facilities."

More than 125 US aircraft participated in this mission, including B-2 stealth bombers, multiple flights of fourth- and fifth-generation fighters, dozens of air refueling tankers, a guided missile submarine, and a full array of intelligence, surveillance, and reconnaissance aircraft, as well as hundreds of maintenance and operational professionals, Caine said.

It was the "largest" B-2 operational strike in US history and the second-longest B-2 mission ever flown, exceeded only by those in the days following 9/11, he added.

He said the main strike package was comprised of seven B-2 bombers, and they flew for 18 hours from the US into the target area.

"With a total of 14 MOPs (Massive Ordnance Penetrator) dropped against two nuclear target areas," Caine said.

Caine said, according to the initial battle damage assessments, all three sites sustained "extremely severe" damage and destruction.

In total, he said the US launched approximately 75 precision-guided weapons during the operation.

"Our forces remain on high alert and are fully postured to respond to any Iranian retaliation or proxy attacks, which would be an incredibly poor choice," Caine stressed.

"We've made smart decisions to minimize the risk to US forces in the region," Caine said, noting that the US troops in the region were given "no advance warning" of Iran strikes.

Asked when congressional leaders were notified, and how long before the attacks took place, Hegseth said they were notified after the planes were "safely out."

"They were immediately thereafter," he added.

US lawmakers on Saturday blasted Trump's "unilateral" action to strike Iran without seeking congressional authorization.

The US "certainly" understands the challenges of allies in the region, Hegseth said. "We have been respectful and have been working in collaboration with them."

When asked about the US getting into "another open-ended war" in the Middle East over weapons of mass destruction, Hegseth said: "I would just say, as the president has directed and made clear, this is most certainly not open-ended... We will respond if necessary."