Deputy Foreign Minister Danny Ayalon warned German Defense Minister Thomas de Maiziere that heavy pressure must be immediately applied to Iran "until it breaks," speaking during a panel at the Munich Conference on Friday.
"We do not have the privilege to wait on the results of sanctions against Iran," Ayalon told de Maiziere. Germany, he added, "as the strongest country in the European Union," must send a message to policy-makers in those European countries that are reliant on Iranian oil to break their reliance on it in order for EU sanctions to be significant.
Ayalon said there had been "very, very positive steps" in toughening curbs on Iran including EU sanctions, although some of these might only take affect gradually over some months.
"It is not enough yet in the sense that the lead time is a little bit too much, I believe the crunch should be now. It is a matter of weeks and months that can make a difference," he said.
"We know that Iran is actually accelerating its nuclear activities maybe to preempt sanctions, so this is why now is the time to do it, so the Iranians will blink. The Iranian regime, as fanatic, as radical, as dangerous as it is, it's not irrational when it comes to its own political survival."
"Now the dilemma will all be theirs. They will have the dilemma to stop or bear the consequences."
Speaking to Reuters on the sidelines of the conference in Germany, Ayalon added that the key point of international concern should be the amount of enriched uranium Iran has managed to bury at a deep site at Fordow, its best sheltered nuclear site south of Tehran.
Ayalon was responding to a US newspaper report that Defense Secretary Leon Panetta believed Israel was likely to bomb Iran within months to stop it building a nuclear bomb.
He added: "I don't want to get into specifics because I don't think we may necessarily reach that fork in the road of taking such a decision by all of us in the international community, if indeed sanctions will be imposed now, and the Iranians will stop completely their illegal activities now, then we may not even need to discuss such issues."