The only conservative challenger to Iranian President Mahmoud Ahmadinejad in Iran's elections proposed on Wednesday a step-by-step approach to improve US 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. A Rezaei victory, however, could bring greater complications for any interplay with Washington. He is wanted by Interpol in connection with a 1994 bombing of a Jewish center in Argentina that killed 85 people. Iran has rejected the warrants as politically motivated. Rezaei, 57, told the AP he seeks a step-by-step "reciprocal change" plan to end the diplomatic estrangement with the United States since shortly after the 1979 Islamic Revolution. He proposed starting with non-confrontational issues such as setting up a committee to protect the Persian Gulf ecosystem or a three-way committee with Pakistan to fight drug trafficking. Later, the two nations could move toward the key impasses such the scope of Iran's nuclear program. "The issue of Iran-US relations is now up in the air," he said at his campaign headquarters in Teheran. "I'll put an end to this state of no decisions." He called Obama's victory a significant change in US policies on Iran. "The West has become disappointed of overthrowing the Islamic republic of Iran and feels that it should no longer continue its previous 30-year policy," he said. "Fundamental changes have occurred in the US society. President Barack Obama is the result of this change. Americans no longer look at the adventurist policy of invading other countries." Last month, Defense Secretary Robert Gates said tighter sanctions may be more effective than military threats in the standoff over Iran's nuclear program. Iran says it only seeks energy-producing reactors, but the United States and some of its allies worry Teheran could use its enrichment facilities to produce weapons-grade nuclear material. Iran also raised worries about its ambitions to bolster its conventional arsenal after the test-firing last week of an advanced missile with a range of about 1,200 miles, far enough to strike Israel, southeastern Europe and US bases in the Middle East. But he did say Ahmadinejad's questioning of the Holocaust "not useful" for Iran's international standing. The two reformist candidates, Mousavi and Mahdi Karroubi, also have vowed to improve ties with the US and meet Obama if that would help Iran's national interests, but they have not offered detailed plans. On Monday, Ahmadinejad proposed a face-to-face debate with Obama at the United Nations if he is re-elected next month. But Ahmadinejad balanced the offer with a sharp rebuke to Washington and its allies over Iran's nuclear program, saying the country would never abandon its advances in uranium enrichment in exchange for offers of easing sanctions or other economic incentives. Rezaei, who holds a doctorate in economics, made clear his campaign would continue to hammer Ahmadinejad on the economy. He even suggested he could form a coalition government with reformists if he wins. "Continuation of Ahmadinejad's policies will take us to the precipice because of his mismanagement, lack of plans and constant replacement of managers. I'm after an economic revolution in Iran. I can do that with the formation of a coalition government," he said. Rezaei said he seeks to bring order to Iran's economy, promote privatization, guarantee foreign investment and stop government's interference. Rezaei has chosen Davood Danesh Jafari, who was Ahmadinejad's economy minister, as his senior adviser. Rezaei enjoys support in his home base of the oil-rich province of Khuzestan in southwestern Iran. He's believed to have the backing of Iran's powerful former president, Akbar Hashemi Rafsanjani, a major figure in the clerical hierarchy.