US President Donald Trump said on Saturday there could be US casualties after he announced the United States began "major combat operations" in Iran.
The strikes, which Trump said were aimed at destroying Iranian missiles and annihilating its navy, follow repeated US-Israeli warnings that they would strike Iran again if it pressed ahead with its nuclear and ballistic missile programs.
"My administration has taken every possible step to minimize the risk to US personnel in the region. Even so, and I do not make this statement lightly, the Iranian regime seeks to kill," Trump said in a video shared on Truth Social, Reuters reported.
"The lives of courageous American heroes may be lost and we may have casualties, that often happens in war, but we're doing this, not for now. We're doing this for the future, and it is a noble mission."
The White House later said there were no confirmed plans for a further address to the nation by Trump, who arrived in Palm Beach, Florida, late on Friday.
The US military has named the operation "Epic Fury," the Pentagon said on X.
This is the second time the US has carried out strikes on Iran since Trump returned to the White House last year. The first was in June when Washington carried out a series of attacks on Iranian nuclear sites.
Saturday's strikes, unlike the first, are expected to be carried out over several days, a US official told Reuters.
Secretary of State Marco Rubio called top congressional leaders known as the "Gang of Eight" before the strike, said Representative Jim Himes of Connecticut, the top Democrat on the House of Representatives' Intelligence Committee.
"Everything I have heard from the Administration before and after these strikes on Iran confirms this is a war of choice with no strategic endgame," Himes said.
"As I expressed to Secretary Rubio when he briefed the Gang of Eight, military action in this region almost never ends well for the United States, and conflict with Iran can easily spiral and escalate in ways we cannot anticipate. It does not appear that Donald Trump has learned the lessons of history."
House Speaker Mike Johnson, also one of the Gang of Eight, said the group had been briefed in detail earlier this week that military action against Iran may be necessary.
Rubio had told the leaders during a briefing at the White House on Tuesday that the operation would likely move forward, but that there were diplomatic efforts to try and strike a deal with Tehran that could change Trump’s thinking, two sources familiar with the matter said.
Rubio notified the Gang of Eight on Friday night that the operation to attack Iran was likely to commence in the following hours but said Trump could still change his mind, the sources said.
In his video message, Trump told the members of the Islamic Revolutionary Guard Corps, Iran's elite armed forces, to lay down their weapons, promising that they would be granted immunity.
The other option, according to Trump, is "certain death."
Washington and Tehran held a series of talks in recent weeks about Iran's nuclear ambitions. The most recent one was held on Thursday with no deal.
"Iran refused, just as it has for decades and decades. They rejected every opportunity to renounce their nuclear ambitions, and we can't take it anymore," Trump said.
The president first floated the idea of strikes on Iran in January amid two-week-long nationwide protests, during which thousands of people were killed by authorities.
He said that the US would come to the rescue of protesters if Iranian officials were to shoot and kill them. Trump later encouraged the protesters to continue protesting, saying that help was on the way.
Trump mentioned the killing of protesters during his statement on the strikes, telling Iranians to take cover because bombs will drop "everywhere".
"When we are finished, take over your government. It will be yours to take. This will be probably your only chance for generations," he said.
