United States President Barack Obama has issued an unprecedented videotaped appeal to Iran offering a "new beginning" of diplomatic engagement to turn the page on decades of policy toward America's longtime foe.
"My administration is now committed to diplomacy that addresses the full range of issues before us, and to pursuing constructive ties," Mr Obama said in a message released on Friday to select Middle East broadcast outlets timed for an Iranian holiday celebration.
He went further than he has since taking office on 20 January in extending an olive branch to Tehran, which has been locked in bitter disputes with Washington over Iranian nuclear ambitions and support for militant Islamic groups.
The Obama administration - in a major shift from former President George W Bush's isolation policy towards Iran, which he once branded part of an "axis of evil" - has expressed an openness to face-to-face diplomatic contacts with Tehran.
The United States is at loggerheads with Iran over its nuclear programme, which Washington says is aimed at building atomic weapons, while Tehran insists it is for the peaceful generation of electricity.
Mr Obama has also insisted that Iran end support for groups the US considers terrorist organisations and cease "bellicose language" toward American ally Israel.
A senior adviser to Iranian President Mahmoud Ahmadinejad welcomed Mr Obama's message, but said the US president had "to go further than words and take action", AFP reported.
Ali Akbar Javanfekr said differences between the two countries were the result of the "hostile, aggressive and colonialist attitude of the American government" and that the US had to recognise its past mistakes if it wanted to engage Iran.
The US cut off diplomatic ties with Iran during the 1979-1981 hostage crisis, in which a group of militant Iranian students held 52 American diplomats hostage at the American Embassy for 444 days.