Iran's supreme leader Ayatollah Ali Khamenei said on Saturday the Islamic republic is willing to change if US President Barack Obama leads the way by changing American attitude towards his country.
Speaking a day after Mr Obama offered Tehran a "new beginning" to turn back the tide on decades of mutual animosity, Ayatollah Khamenei said Iran is yet to see any change in Washington's attitude towards Tehran.
"We have no experience with the new American government and the new American president. We will observe them and we will judge. If you change your attitude, we will change our attitude," Ayatollah Khamenei said in an address to thousands of Iranians in the holy city of Mashhad which was broadcast on state television.
Tehran, he said, had yet to see any change in US policy towards Iran.
While reaching out to Iran, Mr 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," Ayatollah Khamenei said. During his televised speech, the crowd chanted: "Death to America."
In a major shift from the policies of his predecessor George Bush, who branded Iran part of an "axis of evil" and spearheaded a drive to isolate it, Mr 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.
In his warmest offer yet of a fresh start in relations, Mr Obama said in his video message released to mark the Iranian New Year: "The United States wants the Islamic Republic of Iran to take its rightful place in the community of nations."
"That place cannot be reached through terror or arms," he said, "but rather through peaceful actions that demonstrate the true greatness of the Iranian people and civilization."