US strikes against Iran not aimed at regime change: Pentagon chief

Washington: The US military's strikes on Iran's nuclear sites were not a preamble to plans for regime change, US Defense Secretary Pete Hegseth said on Sunday, adding that private messages had been sent to Tehran encouraging them to negotiate.

Still, Hegseth warned Iran against following through with past threats of retaliation against the United States, and said US forces were postured to defend themselves, and take action if needed.

"This mission was not and has not been about regime change," Hegseth told a reporters at the Pentagon. "The president authorized a precision operation to neutralize the threats to our national interests posed by the Iranian nuclear program."

Track latest updates on West Asia conflict here.

The US strikes included 14 bunker-buster bombs, more than two dozen Tomahawk missiles and over 125 military aircraft, in an operation the top US general, General Dan Caine, said was named "Operation Midnight."

Caine said initial battle damage assessments indicated that all three sites sustained extremely severe damage and destruction, but he declined to speculate whether any Iranian nuclear capabilities might still be intact.

The operation pushes the Middle East to the brink of a major new conflagration in a region already aflame for more than 20 months with wars in Gaza and Lebanon and a toppled dictator in Syria.

Tehran has vowed to defend itself, and responded with a volley of missiles at Israel that wounded scores of people and destroyed buildings in its commercial hub Tel Aviv.

But, perhaps in an effort to avert all-out war with the superpower, it had yet to carry out its main threats of retaliation - to target US bases or choke off the quarter of the world's oil shipments that pass through its waters.

The Iranian parliament approved closing the Hormuz strait, a potential choke point for oil shipments, but the country's top security body is required to make a final decision, Iran's press TV reported.

Caine said the US military had increased protection of troops in the region, including in Iraq and Syria.

"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 said.