"We have achieved a historic victory," Netanyahu said in a televised address to the nation after the start of a ceasefire agreed to by both countries.

"Iran will never have a nuclear weapon," he told viewers in the near-10-minute speech.

"We have thwarted Iran's nuclear project. And if anyone in Iran tries to rebuild it, we will act with the same determination, with the same intensity, to foil any attempt," he added.

The head of Israel's military Eyal Zamir said earlier on Tuesday that its strikes had set back Iran's nuclear programme "by years" and the campaign against the country was now "entering a new phase".

Iran said on Tuesday that it was ready to return to nuclear negotiations with the United States as the ceasefire took hold.

But Iranian President Masoud Pezeshkian said his country would continue to "assert its legitimate rights" to the peaceful use of atomic power.

Israel's government said in a statement earlier Tuesday that it had removed the "dual existential threat" of Iran's nuclear programme and missiles during its strikes.

Netanyahu claimed that Israel's attack on Iran, named "Operation Rising Lion", would be "recorded in the annals of Israel's wars, and will be studied by armies all over the world."

It included repeated strikes on Iran's nuclear and missile sites, assassinations of military and domestic security service leaders, as well as the bombing of state media and Evin prison in Tehran.

After the United States joined in the conflict with strikes on Sunday, President Donald Trump said his forces had "totally obliterated" Iran's main nuclear sites.

Analysts said, however, that it remained unclear whether the strikes had put the nuclear threat out of reach, with the possibility that Iran had moved its stockpiles of highly enriched uranium away from the targeted sites.

Tehran has always denied seeking a nuclear weapon.