Iran's former reformist president says he'll challenge hard-line President Mahmoud Ahmadinejad in the country's upcoming presidential elections.

Mohammad Khatami made the announcement Sunday during a meeting with his supporters.

The 65-year-old Khatami was Iran's president from 1997 to 2005. His landslide victory in 1997 defeated hard-liners who ruled the Islamic Republic since the 1979 Islamic Revolution.

He is credited with relaxing some of Iran's rigid restrictions on cultural and social activities. But he left office widely discredited among his political base.

Iran's presidential elections are set for June 12. Ahmadinejad is seeking his second term. Moderate Iranian cleric Mehdi Karrubi has also said he'll run.