A nuclear deal struck between Iran and world powers in Geneva was "bad" as Tehran had obtained "what it wanted", Israeli Prime Minister Benjamin Netanyahu's office said Sunday.

"This is a bad agreement that gives Iran what it wanted: the partial lifting of sanctions while maintaining an essential part of its nuclear programme," said a statement published a few hours after the historic accord was signed in the Swiss city.

"The agreement allows Iran to continue to enrich uranium, leaves the centrifuges in place and allows it to produce fissile material for a nuclear weapon," it added.

"The accord did not lead to the dismantling of the Arak plant", the heavy water reactor being built 240 kilometres (150 miles) southwest of Tehran.

"Economic pressure on Iran could have produced a much better agreement that would have led to a dismantling of Iran's nuclear capacities," the statement said.

Israel's Economy Minister Naftali Bennett, the leader of a far-right party, meanwhile said his country was not bound by the Geneva deal and had a right to self-defence.

"Iran is threatening Israel and Israel has the right to defend itself," he told a military radio station.

Foreign Minister Avigdor Lieberman too railed against the deal.

"This agreement is the greatest diplomatic victory of Iran, which has gained recognition for its so-called legitimate right to enrich uranium," Lieberman told public radio.

The hawkish, blunt-talking chief diplomat, who returned to office earlier this month after seeing off graft charges, stressed that "all options are on the table".

"The responsibility for the security of the Jewish people and the population of Israel remains the sole responsibility of the Israeli government," Lieberman said.

"All decisions in this regard will be taken independently and responsibly," he added.

US Secretary of State John Kerry, a key player in the marathon talks that led to the interim deal, had earlier tried to head off criticism by Israel by saying it would make the Jewish state more secure.

"This first step, I want to emphasise, actually rolls back the programme from where it is today, enlarges the breakout time, which would not have occurred unless this agreement existed. It will make our partners in the region safer. It will make our ally Israel safer," Kerry told reporters.

Ahead of the deal, Israel had issued repeated broadsides, warning that any easing of sanctions against Iran could enable a "breakout" -- a final leap towards acquiring atomic weapons.

Israel -- widely assumed to be the Middle East's only atomic-armed nation -- has refused to rule out military action against Iran, its arch-foe, to halt its nuclear programme in its tracks.

Netanyahu has also warned the West against being hoodwinked by Iran's apparent newfound appetite for rapprochement with the West since President Hassan Rouhani, himself a former nuclear negotiator and seen as a relative moderate, replaced hardliner Mahmoud Ahmadinejad in August.

Kerry said Netanyahu -- "a friend of mine" -- had been kept abreast of the state of play in the talks, which kicked off Wednesday.

"I talk to him several times a week," he said. "I talked to him in the last day about this very issue."

Any differences between the United States and Israel on the issue were simply a matter of "judgement" and "calculation", Kerry insisted.

"There is no difference whatsoever between the US and Israel of what the end goal is -- that Iran will not have a nuclear weapon," he added.