The only two reformist challengers to hard-line President Mahmoud Ahmadinejad in upcoming elections vowed Saturday to bring change to Iran and restore the country's dignity.

Mir Hossein Mousavi, the leading reformist candidate in the June 12 vote, said he will improve Iran's economy and relations with the international community that suffered under Ahmadinejad's hard-line rule.

"I've come to be a means of restoring Iranian power, dignity and identity," Mousavi told reporters after formally registering as a candidate Saturday.

Mousavi, a popular ex-prime minister and former hard-liner, has tried to define himself as capable of straddling Islamic values and the freedom necessary to liberalize Iran's economy and politics.

The other reformist challenger, Mahdi Karroubi, said he will reverse Ahmadinejad's policies that brought international isolation and harmed Iran's economy. The former parliament speaker has said he wouldn't mind meeting President Barack Obama if it would help Iran's national interest.

Karroubi told reporters after registering that reformists view Ahmadinejad and his allies "as weak for administering the country."

Many conservatives and reformists have criticized Ahmadinejad's handling of the economy, accusing him of focusing too much on Iran's standoff with the West over the country's nuclear program rather than on worsening inflation and unemployment.

The only conservative challenger to Ahmadinejad is Mohsen Rezaei, a former head of Iran's elite Revolutionary Guards. He has also blamed Ahmadinejad for Iran's economic woes, vowing to "save" Iran's economy if elected.

Rezaei is not seen as a leading challenger to Ahmadinejad, but reformists hope he will siphon conservative votes away from the president, strengthening the chances of reformists, who seek an easing of social and political restrictions at home and better ties with the West.

Ahmadinejad, who formally registered his candidacy Friday, has not spelled out his plans but said that "serving the Iranian nation is the biggest honor."