Romney added that he still leaves the option of military action "on the table" should it be needed.
Romney's remarks came as he told reporters Friday afternoon about the phone conversation he had just finished with Israeli Prime Minister Bibi Netanyahu.
During the conversation, Romney said it was made clear that he and Netanyahu have "very much have the same interest to make sure that Iran does not develop nuclear capability, which would threaten the existence of Israel, threaten devastation potentially in other nations of the world, and we must make every effort to prevent them from developing that nuclear capability."
"I also believe that there is a strategy that would lead us to preventing Iran from developing nuclear capability. I do not believe in the final analysis we will have to use military action," said Romney.
"I certainly hope we don't have to. I can't take that option off the table; it must be something which is known by the Iranians as a possible tool to be employed to prevent them from becoming nuclear," he said. "But I certainly hope that we can prevent any military action from having to be taken."
Romney, who repeated today that he would have encouraged crippling sanctions against Iran earlier than the President did, appeared to soften his tone, no longer declaring with certainty that if Obama is reelected, Iran will get a nuclear weapon.
In his speech to the United Nations on Thursday, Netanyahu, who has for months hinted that Israel would take military action against Iran, also appeared to take a more softened tone.
Netanyahu pushed back to next summer the date by which he believes Iran could get a nuclear weapon, and even offered President Obama, with whom relations have not always been good with, praise for the sanctions he's placed on Iran.