US President Barack Obama offered on Friday in a surprise video a "new beginning" of engagement with Iran, agencies reported.
The president has voiced changes in US policy towards its long-time foe since taking office.
In the video message, he said "my administration is now committed to diplomacy that addresses the full range of issues before us, and to pursuing constructive ties," while admitting "serious differences" that have grown over time between the two sides.
Going further than previous statements, Obama said the United States would seek engagement instead of threats and mutual respect, adding that it will not be advanced by "threats".
He also urged the two countries to resolve their long-standing differences.
He expressed willingness to speak clearly to Iran's leaders and people.
Referring to the contentious issue of Iran's nuclear program, Obama said the right to own nuclear program comes with "real responsibilities", and that "cannot be reached through terror or arms, but rather through peaceful actions that demonstrate the true greatness of the Iranian people and civilization."
"And the measure of that greatness is not the capacity to destroy, it is your demonstrated ability to build and create," he added.
Iran had reacted with caution to the olive branch extended recently by the Obama administration.
In February, Iranian President Mahmoud Ahmadinejad said Iran was ready for "fair talks" with the United States.
"The new US administration has said it wants changes and follow the course of dialogue ... but the changes must be fundamental and not tactical," he said.
Calling for a real change of strategy to pave the way for direct talks,Iranian Parliament Speaker Ali Larijani said "we have to know what their objectives are... practical steps for such a dialogue between Tehran and Washington would be a strategy change."
Analysts said the fact that senior Iranian officials have reiterated on several occasions the United States should make fundamental "change" shows that Tehran is still worried whether the new US administration is repeating Bush's strategy using a different "tone".
(Xinhua News Agency March 20, 2009)