ABOARD THE ROMNEY CAMPAIGN PLANE-- Mitt Romney said Friday following a conversation with Israeli PM Benjamin Netanyahu that he was hopeful that the U.S. wouldn't have to use military force to halt Iran's progress toward nuclear weapons.

The Republican presidential nominee told reporters traveling with him that he thought a peaceful resolution in Iran was still within reach, though Romney cautioned that it was important to leave open the option to use military force.

"I do not believe that in the final analysis we will have to use military action," Romney told reporters traveling with him from Philadelphia to Boston. " I certainly hope we don’t have to."

The GOP presidential nominee, who has long advocated the U.S. taking a tougher stand against the Iranian regime, said despite his optimism it would be important in future negotiations with Iran to keep a military option on 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," Romney said of a possible use of military force. "But I certainly hope that we can prevent any military action from having to be taken."

The remarks came roughly one hour after Romney concluded his telephone conversation with the Israeli prime minister, who delivered an address to the United Nations yesterday in which he advocated for the drawing of a bright "red line" with Iran's leadership - offering a clear point of no return which would trigger Western military action and hopefully dissuade the regime from further pursuing its nuclear program.

Netanyahu also spoke by phone with President Barack Obama earlier today, and Romney was asked to draw a distinction between his views on Iran and those of the president. Romney said the administration's policies have moved more to mirror with his own views over time, pointing to newer, more aggressive sanctions placed on the Iranian regime as evidence, and saying he would continue to see how well Obama would match his rhetoric to his actions.

"His words more recently are more consistent with the words that I’ve been speaking for some time," Romney said. "And we’ll see what actions he pursues."