The only conservative challenger to President Mahmoud Ahmadinejad in Iran''s elections proposed on Wednesday a step-by-step approach to improve U.S. ties and said President Barack Obama has made an important shift in attitude toward Iran.

The comments by Mohsen Rezaei — in an interview with The Associated Press — broadened his attacks on Ahmadinejad to include his handling of foreign affairs and offered clearer hints of his plans for possible outreach to Washington if elected.

He also said he was open to talks with the West on Iran''s nuclear program and proposed forming an international consortium to oversee uranium enrichment in Iran.

Rezaei, a former head of Iran''s powerful Revolutionary Guard, has mostly concentrated his campaign for the June 12 elections on Iran''s faltering economy — one of Ahmadinejad''s most vulnerable points with voters suffering from rising unemployment and 25 percent inflation.

It appears that Rezaei will also attempt to challenge Ahmadinejad over best how to respond to Washington''s opening for dialogue.

Rezaei still faces an uphill fight to swing conservative voters his way. But his campaign has drawn unexpected favor from reformists who hope he can siphon enough conservative votes from Ahmadinejad to put the main pro-reform candidate, Mir Hossein Mousavi, over the top.