Iran has denied it is set to resume nuclear talks with the United States after the end of a 12-day war with Israel, and accused Washington of exaggerating the impact of US strikes.

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. (AFP)