In an interview broadcast Sunday on CNN's State of the Union, Clinton replied with a blunt "no" when asked by CNN Senior Political Correspondent Candy Crowley if Iran had taken up Obama on his offer in his inaugural address last year to "extend a hand if you are willing to unclench your fist."
"But the fact is, because we engaged, the rest of the world has really begun to see Iran the way we see it," Clinton said in the interview conducted Thursday.
Clinton pointed out that a year ago, much of the world, including Russia, did not share the U.S. perception that Iran's nuclear program posed a major threat.
Now there is greater awareness of the threat, Clinton said, due to "a very slow and steady diplomacy plus the fact that we had a two-track process."
"Yes, we reached out on engagement to Iran, but we always had the second track which is that we would have to try to get the world community to take stronger measures if they didn't respond on the engagement front," Clinton said.
On Friday, Iran's foreign minister had said he believed a solution will be reached over the proposed deal to export uranium for enrichment abroad, as demanded by Western nations worried that Tehran plans to use its program to build nuclear weapons.
However, Iranian President Mahmoud Ahmadinejad said Sunday he had ordered Iran's atomic chief to increase the nation's enrichment of uranium at home. Ahmadinejad did not set a deadline for the increase..
"The doors for interaction are still open," Ahmadinejad said at a ceremony marking Iran's laser technology achievements.
An accord on exchanging nuclear fuel could mark a breakthrough in the long-running dispute over Iran's nuclear program, which the West fears could be used to produce an atomic bomb.
Iran, a major oil producer, says it only aims to generate electricity and its nuclear program is intended solely for peaceful purposes.
With regard to North Korea, Clinton said it also has spurned the Obama administration's efforts at engagement over its nuclear ambitions.
"But because we were willing to engage, we ended up getting a very strong sanctions regime against North Korea that China signed onto and Russia signed onto," Clinton said. "And right now is being enforced around the world."