Iran's Supreme Leader Ayatollah Ali Khamenei said on Saturday US President Barack Obama's offer of better ties was just a “slogan”, but pledged Tehran would respond to any real policy shift by Washington. Speaking a day after Obama's videotaped overture, Khamenei, Iran's most powerful figure with final say on all matters of state, said he saw no such change yet from the United States. But he added: “You change, our behavior will change.” Sharply criticizing US actions toward Iran since its 1979 Islamic revolution which toppled the US-backed shah, he said the United States was “hated in the world” and should stop interfering in other countries' internal affairs. “They give the slogan of change but in practice no change is seen ... We haven't seen any change,” Khamenei said. Iran and the US have not had diplomatic ties for three decades and are now embroiled in a dispute over Tehran's nuclear work, which the West suspects is aimed at making bombs. Iran denies the charge. In a major shift from the approach of his predecessor George W. Bush, who branded Iran part of an “axis of evil” and spearheaded a drive to isolate it, Obama has talked of extending a hand of peace to Tehran if it “unclenches its fist”. On Friday, the US president offered a “new beginning” of diplomatic engagement between the two old foes. Khamenei said a change of US “words” was not enough and that Obama had “insulted” Iran and its government immediately after taking office, without elaborating. While reaching out to Iran, Obama's administration has also warned of tougher sanctions if it continues to defy UN demands to halt sensitive nuclear work. “You give the slogan of negotiation and pressure again ... Our nation cannot be talked to like this,” Khamenei said. During his televised speech at Iran's most prominent religious shrine in the northeastern city of Mashhad, the big crowd chanted: “Death to America. Death to America.” In his warmest offer yet of a fresh start in relations, Obama said in his video message released to mark the Iranian New Year: “The US wants the Islamic Republic of Iran to take its rightful place in the community of nations.” He said “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.” Khamenei made clear his view that more was needed from Washington if it wanted better ties with his country. “They say we have extended a hand towards Iran. What kind of hand is this? If the extended hand is covered with a velvet glove but underneath it, the hand is made of cast iron, this does not have a good meaning at all,” he said. ‘What has changed?' Noting Obama's New Year greeting, he added: “In the same congratulatory message they accuse the Iranian nation of supporting terrorism, pursuing nuclear arms and such things ... what has changed?” Analysts have said that Iran is setting tough conditions for dialogue to buy time for its ponderous, opaque decision-making process. Adding to uncertainty, Iran holds a presidential election in June that could strengthen moderate voices backing detente over more hardline opponents. President Mahmoud Ahmadinejad has demanded Washington apologize for decades of “crimes” against Iran. Tehran also says it cannot let down its guard as long as US troops are posted on its borders in Iraq and Afghanistan. Khamenei accused the US of links with “terrorist movements” operating in border areas near Pakistan and also criticized it for freezing Iranian assets and for backing former Iraqi strongman Saddam Hussein during the 1980-88 Iran-Iraq war. “Iran has many grievances and it expects that the United States would finally come to recognize this,” said Prof. Mohammad Marandi of North American studies at Tehran University. “Change does not come about by saying Happy New Year.”