PRESIDENT Barack Obama's videotaped overture to Iran on Friday was the latest in a series of recent US steps to engage its longtime foe but analysts cautioned the process would take time. Follow-up moves will be required, many of which will take place outside of public view, the experts added. “We have to understand that the president has sent signals. He'll have to send them again,” said Anthony Cordesman, a national security analyst at the Center for Strategic and International Studies think tank. Complicating the timetable for engagement is Iran's June presidential election, the outcome of which will influence the way Tehran engages with Washington. Hard-line President Mahmoud Ahmadinejad is seeking reelection against reformist candidates. “If we see any clear payout, it's likely to be after the Iranian elections are over,” Cordesman said. Tehran has been locked in bitter disputes with Washington over Iranian nuclear ambitions and support for militant Islamist groups. In a message timed for the Iranian celebration of Nowruz, a holiday marking the arrival of spring, Obama said he wanted to pursue “constructive ties” with Tehran and engage in broad diplomacy. “The timing was very thoughtful. In acknowledging Nowruz, he showed the Iranian people that he has an appreciation for their culture and history,” said Karim Sadjadpour, a scholar at the Carnegie Endowment for International Peace. Over time, Obama's strategy may pay dividends by forcing hard-liners in Iran “to justify their often gratuitous enmity toward the US,” Sadjadpour said. He agreed with Cordesman that the effort at diplomacy would require patience and probably a fair amount of time. ‘It takes two to Tango' “Ultimately, it takes two to tango, and at the moment hard-liners in Tehran who are not interested in having an amicable relationship with the United States have an inordinate amount of influence,” Sadjadpour added. Aliakbar Javanfekr, an aide to Ahmadinejad, said on Friday that Iran welcomed “the interest of the American government to settle differences” but that Washington “should realize its previous mistakes and make an effort to amend them.” The White House sounded a note of caution when pressed on how quickly it expected results from its strategy. “In terms of reaction or what we hope to get out of it, I think in many ways that's up to Iran,” White House spokesman Robert Gibbs said. “The president believed that the (Iranian) New Year marks ... a good time for us to demonstrate the tone for the type of respectful engagement that we believe can be had with the people of Iran,” he said. Obama, who promised during his presidential campaign to talk to foes like Iran, offered at the start of his administration in January to engage Iran if it “unclenched its fist.” The administration is making a major shift from former President George W. Bush's policy to isolate Iran, which he once branded part of an “axis of evil.” The United States cut off diplomatic ties with Iran during the 1979-1981 hostage crisis, in which a group of militant Iranian students held 52 US diplomats hostage at the American Embassy for 444 days. The video appeal followed other carefully choreographed public overtures, including Obama's comment at a February news conference that he was looking for diplomatic openings with Tehran, and a recent US invitation for Iran to attend an international conference on Afghanistan at the end of this month. Iran has given mixed responses to the US gestures, at times welcoming them but in other instances setting tough conditions for any dialogue with the United States. Iran's supreme leader, Ayatollah Ali Khamenei, made no mention on Friday of Obama's video message but vowed that world powers could not stop Tehran's nuclear progress – raising a central dispute with the West, which accuses Iran of seeking to make a nuclear bomb. Tehran insists its nuclear program is for the peaceful generation of electricity. Obama's overture to Iran was welcomed by US allies. In an interview with Reuters, Britain's ambassador to the United States said the video appeal was “the right way to go.” “That has been part of the public messaging really since the inauguration. We think it is an important underlay for the political moves which are now going ahead and will follow,” Sir Nigel Sheinwald said.