"I am well aware of the difficulties involved in thwarting Iran's attempts to acquire a nuclear weapon," he said, Israel’s Ynet news agency reported.
"However, it is clear to me that without a doubt, dealing with the threat itself will be far more complicated, far more dangerous and far more costly in resources and human life," he added.
The Israeli minister emphasized that diplomatic measures and economic sanctions imposed on Iran “are not enough to stop Iran's nuclear program."
The United States and Israel have repeatedly threatened Iran with a military option in a bid to force the Islamic Republic to halt its nuclear energy program, which Washington and Tel Aviv claim has a military component.
Iran rejects the allegations of pursuing military objectives in its nuclear energy program, arguing that as a committed signatory to the nuclear Non-Proliferation Treaty (NPT) and a member of the International Atomic Energy Agency (IAEA), it has the right to use nuclear technology for peaceful purposes.
Barak's comments about Israel's tough decisions to confront a nuclear Iran come while the Israeli regime has illegally built a nuclear power plant and has hundreds of atomic bombs.
Unlike Iran, Israel is a non-signatory to the NPT and continues to defy international calls to join the treaty.
Israel, which is widely believed to possess between 200 to 400 nuclear warheads, maintains a policy of deliberate ambiguity over its nuclear work