In a video address after the United States and Israel started bombing Iran, Trump made clear that the goal was sweeping -- the toppling of the Islamic republic in charge since the 1979 revolution.

"We are going to destroy their missiles and raze their missile industry to the ground. It will be totally -- again -- obliterated. We're going to annihilate their navy," Trump said in the address he posted to his Truth Social platform.

"To the great proud people of Iran, I say tonight that the hour of your freedom is at hand," he said.

"Stay sheltered. Don't leave your home. It's very dangerous outside. Bombs will be dropping everywhere. When we are finished, take over your government. It will be yours to take."

Trump urged Iranian forces to surrender, including the elite Revolutionary Guards that is tasked with safeguarding the cleric-run government.

"To the members of the Islamic Revolutionary Guard, the armed forces, and all of the police, I say tonight that you must lay down your weapons and have complete immunity or in the alternative, face certain death," Trump said.

The attack was widely expected after Trump ordered the biggest military deployment to the Middle East in years.

But Trump on Friday had insisted that he had not decided whether to attack, and his envoys on Thursday held talks with Iran's top diplomat toward a deal on concerns led by Tehran's nuclear program.

The top diplomat of Oman, which mediated talks Thursday in Geneva between the United States and Iran, had been optimistic for a compromise.

He met Friday with Vice President JD Vance and told CBS News that Iran had agreed to zero stockpiling of enriched uranium that could build an atomic bomb, a goal denied by Tehran.

Trump in June ordered the US military to bomb Iran's main nuclear sites in support of an Israeli military campaign.

But he suggested Saturday that the ambitions were far larger, looking to topple the state that has been a nemesis to the United States and Israel since the fall of the pro-Western shah in 1979.