Supreme Leader Ayatollah Ali Khamenei accused US President Donald Trump on Thursday of exaggerating the impact of US strikes on Iranian nuclear sites, in his first appearance since a ceasefire in the war with Israel took hold.

In a televised speech on Thursday, Khamenei hailed what he described as Iran's "victory" over Israel, vowed never to yield to US pressure and insisted Washington had been dealt a humiliating "slap."

"The American president exaggerated events in unusual ways, and it turned out that he needed this exaggeration," Khamenei said, rejecting US claims Iran's nuclear programme had been set back by decades.

The strikes, he insisted, had done "nothing significant" to Iran's nuclear infrastructure.

'Too heavy to be moved out'

Trump, however, maintained the US attacks were devastating.

The US president said key facilities, including the underground Fordow uranium enrichment site, had been "obliterated" by American B-2 bombers.

Posting on his Truth Social platform, Trump dismissed speculation Iran might have removed enriched uranium prior to the raid, saying: "Nothing was taken out... too dangerous, and very heavy and hard to move!"

He added that satellite images showed trucks at the site only because Iranian crews were attempting to shield the facility with concrete.

Iran 'won': Khamenei

Khamenei dismissed such claims, saying "the Islamic republic won, and in retaliation dealt a severe slap to the face of America."

His remarks followed the end of a 12-day war between Iran and Israel – the deadliest between the two countries to date.

Both sides have claimed victory: Israeli Prime Minister Benjamin Netanyahu called it a "historic win", while Khamenei said Iran's missile retaliation had brought Israel to the brink of collapse.

In Washington, the true impact of the strikes has sparked sharp political and intelligence debates.

Contrasts in assessment

A leaked classified assessment suggested the damage to Iran's nuclear programme may be less severe than initially claimed – possibly delaying progress by only a few months.

This assessment contrasts with statements from senior US officials.

CIA Director John Ratcliffe said several facilities would need to be "rebuilt over the course of years."

Pentagon chief Pete Hegseth accused the media of misrepresenting the operation.

Bunker-buster bombs

He said the United States used massive GBU-57 bunker-buster bombs on Fordow and another underground site, while submarine-launched Tomahawk missiles targeted a third facility.

"President Trump created the conditions to end the war, decimating – choose your word – obliterating, destroying Iran's nuclear capabilities," Hegseth said.

Doubts remain about whether Iran quietly removed some 400 kilogrammes (880 pounds) of enriched uranium from its most sensitive sites before the strikes – potentially hiding nuclear material elsewhere in the country.

Following waves of Israeli attacks on nuclear and military sites and retaliatory missile fire from Iran since mid-June, the US bombed three key Iranian atomic facilities.

Critical components 'not destroyed': CNN report

Initial intelligence reports, first revealed by CNN, suggested the strikes did not destroy critical components and delayed Iran's nuclear programme only by months.

Experts questioned if Iran had pre-emptively moved enriched uranium to protect it. The US administration has forcefully rejected such suggestions.

Trump described the attack as having "obliterated" Iran's nuclear facilities, including the Fordow site, which is buried inside a mountain, and claimed it had set back the program by "decades".

The Israeli military said it delivered a "significant" blow to Iran's nuclear sites but cautioned it was "still early" to fully assess the damage.

Netanyahu said Israel had "thwarted Iran's nuclear project", warning any attempt by Iran to rebuild it would be met with the same determination and intensity.