Israel’s leaders have been insisting for months that “no deal is better than a bad deal with Iran,” so a decision Monday to extend negotiations between world powers and Iran over its nuclear program was greeted here with relief.

As news of an extension of the talks into next year emerged from Vienna, Israeli Prime Minister Benjamin Netanyahu told the BBC: “The fact that there’s no deal now gives [the United States and the other negotiating nations] the opportunity to continue the economic pressures that have proven to be the only thing that have brought Iran to the table.”

Netanyahu said that current sanctions against Iran should not only be maintained but tightened in the coming months as talks, extended until July, continue.

The prime minister has spent the past three years repeatedly warning the Obama administration and Congress that an Iran with nuclear weapons and long-range missiles would pose a threat not only to Israel but also to Europe and others.

Netanyahu said that, as talks go forward, economic sanctions are “the route that needs to be taken.”

Secretary of State John F. Kerry said Monday that diplomats have given themselves an additional seven months to reach a comprehensive nuclear agreement, though talks in Vienna have made “real and substantial progress.” (Reuters)

He added, “But of course Israel is watching very carefully what is happening here, and Israel always — always — reserves the right to defend itself.”

A senior Israeli official, who spoke on the condition of anonymity to describe internal government assessments, said: “I think you can use the word ‘relief.’ There was real concern that a bad deal was in the cards.”

Israel has taken a hard line on Iran’s nuclear ambitions, arguing that the sanctions should be made even more punishing and that they should not be lifted until Iran dismantles the centrifuges it uses to enrich uranium. Iran maintains that it needs the uranium-enrichment program to produce fuel for nuclear power plants and a medical research reactor. But Israel, the United States and other nations fear that the program could be used to make highly enriched uranium, which can serve as fissile material in nuclear weapons.

Netanyahu has argued that the United States should not make a deal that delays by only a few months — or even a year or two — the time it would take for Iran to reach “breakout” capacity, enabling it to make a nuclear weapon.

“We must not dismantle sanctions before we dismantle Iran’s capacity to produce a nuclear bomb,” the Israeli prime minister told the ABC News program “This Week” on Sunday.

Netanyahu has charged that Iran “is doing things we don’t know about” and that it is continuing a secret military program during the negotiations.

Israeli Intelligence Minister Yuval Steinitz said in an interview: “There are some saying that these talks were a failure because there were no results, but in my view, this is not the case. It does not have to be seen as a failure. If you insist on your principles and decide that the future of the world is too important to give in to Iranian tricks, then I would not call it a failure.”

Steinitz said Israel understands that one of the main obstacles was Iran’s refusal to dismantle its centrifuges. “If they don’t neutralize all 20,000, then their breakout time, or the time it takes for them to reassemble them, is only a few months,” he said.

“The pressure on Iran was strong, but not enough,” he said. “You have to increase the economic pressure to get better results. There is no other choice if the Iranians want to save their economy from total collapse. Then they will have to agree finally on more significant concessions.”

Ruth Eglash contributed to this report.