Chairman of the Joint Chiefs of Staff Mike Mullen said Sunday the United States has a plan in place to attack Iran, if it is necessary.

"Military actions have been on the table and remain on the table" for curbing Iran's nuclear ambition," Mullen, the highest-ranking U.S. military officer, told NBC's "Meet the Press". When asked if the military has a plan in place to attack Iran if it is needed, he replied: "we do."

"I hope we don't get to that, but it's an important option, and it's one that's well understood," he said.

But Mullen said attacking Iran would not be the best option Washington seeks "not just for the consequences of the action itself, but the things that could result after the fact."

According to him, the so-called "dual-track" strategy, or the combination of multilateral diplomacy and international sanctions, remains the preferred option to suspend Tehran's nuclear program.

Mullen's remark followed Israeli Defense Minister Ehud Barak's trip to Washington.

The United States, Israel and their allies worry that Tehran may obtain the uranium fuel needed for developing nuclear weapons. That claim was rejected by Iranian government which insists its nuclear program is for peaceful purpose.

The Obama administration has been trying the "dual-track" strategy to bring the international community together to make Iranian leaders realize the "importance of changing their actions and decisions concerning their nuclear program."

After pushing the UN Security Council to adopt the Resolution 1929 for imposing more sanctions on Iran in June, the administration has trying to make more countries to take unilateral sanctions against Tehran.

But the Israeli government has been skeptical that Washington's "dual-track" efforts would not effectively prevent Tehran from developing nuclear weapons, which Israel says would pose severe threat to its security.

The Israelis have refused to rule out the possibility on launching unilateral military strike against Iran's nuclear facilities.