US Joint Chiefs of Staff chairman Martin Dempsey has said that it is "premature" to use military force against Iran over its nuclear program. A conflict with Iran now will be "economically destabilizing", he said.

"I do think the path we're on -- the economic sanctions and the diplomatic pressure -- does seem to me to be having an effect," Dempsey said, adding "I just think that it's premature to be deciding that the economic and diplomatic approach is inadequate."

"A conflict with Iran would be really destabilizing, and I'm not just talking from the security perspective," he said. "It would be economically destabilizing," he said in an interview with the National Journal.

The US and its allies are pressuring Iran to engage in talks over its nuclear program. They say it is a cover for making nuclear weapons. Iran has denied the claim.

Dempsey's remarks came two days after President Barack Obama vowed to keep all options on the table to force Iran to abandon its nuclear ambitions, Xinhua reported Thursday.

"America is determined to prevent Iran from getting a nuclear weapon, and I will take no options off the table to achieve that goal," the president said in his annual State of the Union address Tuesday night.