Mofaz's comments, made at a prestigious academic conference in the coastal town of Herzliya, stopped short of overtly threatening a military strike. But his comments were likely to add to the growing tensions with Iran.
Israel has long identified Iran as its biggest threat and accuses the Tehran government of pursuing nuclear weapons. Iran says its atomic programme is peaceful.
Mofaz welcomed the US-led effort to bring Iran before the UN Security Council, saying sanctions and international oversight of Iran's nuclear programme is the "correct policy at this time." But he suggested that Israel is preparing for military action if the diplomatic efforts fail.
Israeli leaders have repeatedly said they hope the crisis can be resolved through diplomacy, and that any military action would have to be part of an international effort. Israeli officials have denied having plans for a unilateral preventive strike.
Israel's concerns about Iran have grown since the election of Iranian President Mahmoud Ahmadinejad, who said last year that Israel should be "wiped off the map."
Mofaz accused Iran of helping mastermind a suicide bombing that wounded 20 people in Tel Aviv last week.
During a trip to Syria last week, Ahmadinejad met with leaders of Islamic Jihad, the group that carried out the bombing, and challenged Europe to take back the Jews who emigrated to Israel. It was the latest in a string of comments questioning Israel's existence.
Mofaz has also said that Israel will have to take further unilateral action in the West Bank if it concludes the Palestinians are not a serious peace partner.
He said that said such moves would not be a substitute for a permanent peace agreement with the Palestinians based on the US-backed "road map." But if peace efforts remain at a standstill following Palestinian elections this week, he said further unilateral action might be necessary.Güncelleme Tarihi: 20 Eylül 2018, 18:16