The most serious conflict yet between Israel and Iran derailed nuclear talks between Iran and the United States, yet President Donald Trump said Washington would hold discussions with Tehran next week, with his special envoy Steve Witkoff expressing hope "for a comprehensive peace agreement".

But Iran's Foreign Minister Abbas Araghchi shut down what he said was "speculation" that Tehran would come to the table and said it "should not be taken seriously".

"I would like to state clearly that no agreement, arrangement or conversation has been made to start new negotiations," he said on state television. "No plan has been set yet to start negotiations."

Araghchi's denial came as Iranian lawmakers passed a "binding" bill suspending cooperation with the UN nuclear watchdog and after supreme leader Ayatollah Ali Khamenei accused Trump of exaggerating the impact of US strikes on Iranian nuclear sites.

In a televised speech -- his first appearance since a ceasefire in the war with Israel -- 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. Araghchi, for his part, called the damage "serious" and said a detailed assessment was under way.

Trump said key facilities, including the underground Fordo uranium enrichment site, had been "obliterated" by American B-2 bombers.

Posting on his Truth Social platform, he 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.

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

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.

- US defence -

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

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.

That 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.

He said the United States used massive GBU-57 bunker-buster bombs on Fordo 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.

- Netanyahu says Iran 'thwarted' -

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

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.

The Israeli military said Iran's nuclear sites had taken a "significant" blow, 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.

Iran has consistently denied seeking a nuclear weapon while defending its "legitimate rights" to the peaceful use of atomic energy.

It has also said it is willing to return to nuclear negotiations with Washington.

The Israeli strikes on Iran killed at least 627 civilians, Tehran's health ministry said.

Iran's attacks on Israel killed 28 people, according to Israeli figures.

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