Prime Minister Benjamin Netanyahu said on Tuesday that a "bad deal" with Iran could lead to war. "On Iran," he said, "there aren't only two options – a bad deal or war. There is a third option: Continuing to exert pressure through sanctions." "I would even say that a bad deal could lead to the second, unwanted result," he added.

On the talks with Iran currently underway in Geneva, Netanyahu said that "a good deal can be achieved and [Iran] can be dismantled [of its weapons], but this is not achieved through negotiations in Geneva."

Iran and the six world powers - the United States, France, Germany, Russia, Britain and China - edged close to a preliminary nuclear accord during negotiations last weekend and decided to meet again there on Nov. 20.

Also on Wednesday, Strategic Affairs Minister Yuval Steinitz said the sanctions relief package offered to Iran as part of nuclear negotiations could be worth up to $40 billion to Tehran.

Steinitz said Israel believed the sanctions put in place by the United States and European Union last year cost Iran's economy around $100 billion per year, or nearly a quarter of its output.

"The sanctions relief directly will reduce between 15 to 20 billion dollars out of this amount," Steinitz said on Wednesday at an English-language event hosted by the Jerusalem Press Club.

Amano: enrichment continues

Meanwhile, the head of the UN nuclear agency said on Wednesday he saw "no radical change" in Iran's nuclear program in the past three months, broadly covering the period since relative moderate Hassan Rohani became president.

Yukiya Amano, director general of the International Atomic Energy Agency, told Reuters that the Islamic Republic was continuing its most sensitive nuclear activity, enrichment of uranium to a fissile concentration of 20 percent.

But his comments suggested that Iran during the August-November period had also not sharply expanded its uranium enrichment work, which Tehran says is peaceful but the West fears could be used to develop nuclear weapons.

In addition, Amano said Iran still had "quite a lot to do" in order to complete the Arak research reactor, a plant which is of deep concern to the West as it can produce plutonium, another potential atomic bomb fuel, once it is operating.

The IAEA is expected to issue its next quarterly report on Iran - a document keenly scrutinised by Western governments - on Thursday or Friday this week. It will be the first that only covers developments after Rohani took office.

"I can say that enrichment activities are ongoing ... no radical change is reported to me," Amano, a veteran Japanese diplomat, said in an interview in his office on the 28th floor of the IAEA's headquarters in Vienna.

He spoke two days after Iran agreed to give his inspectors access to two nuclear-related facilities as part of a cooperation pact that aims to allay international concern about the country's nuclear program.

Amano said the agreement was an important first step towards clarifying outstanding issues between the UN agency and Tehran, including suspicions that Iran has carried out atomic bomb research, a charge Tehran denies.

Iran rejects Western accusations that it is seeking the capability to make nuclear weapons. But its refusal so far to curb its program and lack of full openness with UN anti-proliferation inspectors have drawn tough Western sanctions.

Rohani, a pragmatist, succeeded conservative hardliner Mahmoud Ahmadinejad in August promising to try to settle the decade-old nuclear dispute and secure an easing of sanctions that have severely hurt Iran's oil-dependent economy.

U.S. Secretary of State John Kerry said Monday that Netanyahu "needs to recognize that no agreement" with Iran has been reached and his opposition is premature.  In a tense meeting with Kerry ahead of his departure to Geneva last week, Netanyahu said that Israel does not see itself committed to any deal reached between the P5+1 and Iran in their negotiations.