The United States has bombed three nuclear sites inside Iran, with Donald Trump warning, "future attacks would be far greater and a lot easier".
"I can report to the world that the strikes were a spectacular military success," he said during a White House address tonight.
"Iran's nuclear enrichment facilities have been completely and totally obliterated."
The extent of the damage at the Fordow, Natanz, and Isfahan sites could not be independently verified.
The US Air Force's B-2 Spirit stealth bombers were involved in the strikes, with Reuters reporting six bunker-buster bombs were used on the Fordow research site buried deep in the hills of Iran.
Mr Trump called the moment historic for the "US, Israel, and the world" and said, "Iran must now agree to end this war".
After dropping the bombs, Mr Trump said now was the time for peace, but moments ago, Reuters reported an Iranian state television commentator declared: "Every American citizen and military personnel in the region is now a target."
Officials and state media in Iran downplayed the damage, claims that also could not be independently verified.
Iran threatens shipping channel
In response to the attack on the Fordow facility, a representative of Ayatollah Ali Khamenei, Hossein Shariatmadari, said Iran was ready to respond.
"Now it is our turn to, without wasting time, as a first step, fire missiles at the US naval fleet in Bahrain and at the same time close the Strait of Hormuz to American, British, German and French ships," he said in the hardline Kayhan newspaper.
Mr Trump reiterated his warning that the United States was willing to continue its aerial campaign on Iran.
"Any retaliation by Iran against the United States of America will be met with force far greater than what was witnessed tonight," he said in a late-night post to Truth Social.
Earlier in his White House address, Mr Trump said he decided long ago the US would intervene if he felt that was needed to protect American lives.
"There will be either peace or there will be tragedy for Iran, far greater than we have witnessed over the last eight days. Remember, there are many targets left," he said.
Mr Trump also thanked and congratulated Israeli Prime Minister Benjamin Netanyahu, saying the pair had "worked as a team like perhaps no team has ever worked before".
The president said all planes "were now outside of Iranian airspace" and that a "full payload of bombs" was dropped on the primary site of the Fordow nuclear bunker, a heavily fortified facility built underground inside Iran.
"All planes are safely on their way home," he said.
Iranian state media reports 'limited damage'
Inside Iran, there has been confirmation of the strikes, and some reports of explosions from the Fordow and Isfahan areas.
Iranian state media quoted Behrouz Kamalvandi, spokesman for the Atomic Energy Organization of Iran (AEOI), saying the Fordow site experienced limited damage in certain areas.
He said critical equipment and materials had been relocated beforehand, minimising the impact.
Iranian state news agency, Mehr, has reported that the Fordow and Natanz facilities had sustained "limited damage".
The updates from inside Iran could not be independently verified.
One contact inside Iran told the ABC the ground was shaking as if an earthquake had struck.
US politicians react, demand war powers change
The prospect of bombing Iran had not just divided the Congress, but had also been a polarising issue inside Mr Trump's own MAGA camp.
Now that the bombing mission is done, and the United States has entered Israel's war against Iran, there are condemnations as well as support for the president.
Senate foreign relations committee chair Jim Risch, a Republican, said: "This war is Israel’s war, not our war, but Israel is one of our strongest allies and is disarming Iran for the good of the world."
"This is not the start of a forever war. There will not be American boots on the ground in Iran," Mr Risch added.
There are also renewed calls for war powers legislation to be strengthened, so any act such as this would need to have the support of Congress.
Democratic representative Alexandria Ocasio-Cortez of New York said: "The president's disastrous decision to bomb Iran without authorisation is a grave violation of the Constitution and Congressional War Powers."
"He has impulsively risked launching a war that may ensnare us for generations. It is absolutely and clearly grounds for impeachment."
Israel and Iran have been engaged in more than a week of aerial combat that has resulted in deaths and injuries in both countries.
Israel launched the attacks on Iran, saying it wanted to remove any chance of Tehran developing nuclear weapons.
Iran argued its nuclear program was intended for peaceful purposes.
ABC/Reuters