Correction: An earlier version of this article misquoted Israeli Defense Minister Ehud Barak. The quote, which omitted a “not,” should have read: “The dividing line may pass not where the Iranians decide to break out of the nonproliferation treaty and move toward a nuclear device or weapon, but at the place ... that would make the physical strike impractical.” This version has been corrected.

Israeli Defense Minister Ehud Barak said Thursday that time was running out for action against the Iranian nuclear program before it became immune to physical attack, and that dealing with a nuclear Iran would be more difficult than stopping what he called its drive to build an atomic bomb.

His remarks reflected a sense of urgency among Israeli officials, who have urged even tougher sanctions against Iran, targeting its financial system and oil exports, backed by a threat of military action, to compel it to stop its nuclear effort.

“It is obvious that no option should be removed from the table, and that diplomacy must be conducted intensively and urgently,” Barak said before a meeting with German Foreign Minister Guido Westerwelle.

Speaking later at a security conference near Tel Aviv, Barak alluded to Iranian moves to protect its nuclear facilities, including plans to start production at an additional uranium enrichment site near the city of Qom at a new facility buried deep underground.

“Today, as opposed to the past, the world has no doubt that the Iranian military nuclear program is steadily approaching maturity and is about to enter the zone of immunity, after which the Iranian regime will be able to complete the program without effective interruption and at a time it finds convenient,” Barak said.

“The dividing line may pass not where the Iranians decide to break out of the non-proliferation treaty and move toward a nuclear device or weapon, but at the place where the dispersal, protection and survivability efforts will cross a point that would make a physical strike impractical.”

Barak called recently toughened sanctions on Iran “a step in the right direction” but added that they should be tightened “as soon as possible until the aim is achieved, if it is achieved, of stopping the [Iranian] program.”

There was “a broad global understanding that if the sanctions don’t achieve the desired result of stopping the military nuclear program, it will be necessary to consider action,” he said.

Barak rejected criticism that Israeli leaders had failed to consider the full implications of a military strike on Iran’s nuclear facilities. “There is no basis for the claim that this subject . . . was not discussed with appropriate breadth and depth,” he said.

“The assessment of many experts around the world, not only here, is that the result of avoiding action will inevitably be a nuclear Iran, and that dealing with a nuclear Iran will be more complicated, more dangerous and more costly in blood and money than stopping it,” Barak said.

“Whoever says ‘later’ may find that later is too late.”