US President Barack Obama made his warmest offer yet of a fresh start in relations with Iran, which cautiously welcomed the overture but said on Friday it was waiting for “practical steps”, not talk. “My administration is now committed to diplomacy that addresses the full range of issues before us, and to pursuing constructive ties,” Obama said in an unprecedented video message released to Middle East broadcasters to mark Iranian New Year. “This process will not be advanced by threats. We seek instead engagement that is honest and grounded in mutual respect.” Relations have been almost deep-frozen for decades, and remain blighted by differences over Iran's nuclear program, Iraq, Israel and other thorny issues. In separate New Year messages to their nation, neither Supreme Leader Ayatollah Ali Khamenei nor President Mahmoud Ahmadinejad mentioned Obama's offer. Khamenei said world powers had been persuaded they could not block Iran's nuclear progress. But Aliakbar Javanfekr, aide to Ahmadinejad, told Reuters: “The Iranian nation has shown that it can forget hasty behavior but we are awaiting practical steps by the United States. “The Obama administation so far has just talked,” he added, calling for “fundamental changes in his policy towards Iran.” The United States has no diplomatic relations with Tehran, which it accuses of backing militant groups and seeking to develop a nuclear bomb under cover of a civilian atomic power program – a charge Iran denies. Javanfekr said Iran welcomed “the interest of the American government to settle differences.” But he said the US “should realize its previous mistakes and make an effort to amend them.” Washington's sanctions against Tehran were “wrong and need to be reviewed.” Its backing for Israel, Iran's main enemy in the region, was “not a friendly gesture.” The White House distributed the Obama video with Farsi subtitles and posted it on its website. It was not shown or mentioned on Iran's main 2 p.m. state television news, but was reported by Iranian news agencies. Obama has already expressed a readiness to have face-to-face diplomatic contacts with Tehran, a major shift from former President George W. Bush's policy of trying to isolate a country he once branded part of an “axis of evi.” Obama said the United States wanted Iran to take its “rightful place in the community of nations”, but also insisted that Tehran do its part to achieve reconciliation. “You have that right – but it comes with real responsibilities, and that place cannot be reached through terror or arms, but rather through peaceful actions that demonstrate the true greatness of the Iranian people and civilization,” Obama said. “The measure of that greatness is not the capacity to destroy, it is your demonstrated ability to build and create,” he added, apparently alluding to Iran's contested nuclear program and its missile development efforts. President Ahmadinejad has demanded Washington say sorry for decades of “crimes” against the Islamic Republic. Tehran also says it cannot let down its guard as long as US troops are posted on its borders in Iraq and Afghanistan. Obama made no specific offers, but said he wanted “a future with renewed exchanges among our people and greater opportunities for partnership and commerce.” “This won't be reached easily,” he acknowledged. The US cut off diplomatic ties with Iran during a 1979-1981 crisis, when militant Iranian students held 52 US diplomats hostage at the American Embassy for 444 days. Obama said earlier this year he was ready to extend a hand of peace to Iran if it “unclenched its fist.” • Israeli President Shimon Peres sent a rare greeting to the people of Iran, Friday, praising what he called a great and ancient culture and saying they would be better off without their hard