U.S. President Barack Obama sent Iran an unprecedented videotaped message on Friday offering a new beginning of diplomatic engagement after decades of U.S. hostility to the Islamic Republic.

Obama went further than he has since taking office on January 20 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.

In an unusually swift reaction to Obama's overture, a senior official said Iran welcomed the interest of the American government to settle differences.

But Aliakbar Javanfekr, an aide to President Mahmoud Ahmadinejad, said the Obama administration should realize its previous mistakes and make an effort to amend them.

By fundamentally changing its behavior America can offer us a friendly hand, he told Reuters. Unlimited sanctions which still continue and have been renewed by the United States are wrong and need to be reviewed, he said.

Javanfekr singled out U.S. backing for Israel, Iran's main enemy in the region, saying that: Supporting Israel is not a friendly gesture.

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 evil.

In his videotape message, reaching out directly to Iranian leaders and their people, Obama said: My administration is now committed to diplomacy that addresses the full range of issues before us, and to pursuing constructive ties.

This process will not be advanced by threats. We seek instead engagement that is honest and grounded in mutual respect, he said. The message was released to Middle East broadcast outlets to mark an Iranian holiday celebration.

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, alluding to Iran's contested nuclear program and its missile development efforts.

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European Union foreign policy chief Javier Solana said he hoped Iran would pay close attention to Obama's appeal.

I hope that that will open a new chapter in relations with Iran, he told reporters before going into an EU summit.

To stress the seriousness of Obama's overture, the White House distributed the videotape with Farsi subtitles and posted it on its website to coincide with Iranian observance of the ancient festival of Nowruz, celebrating the arrival of spring.

I would like to speak directly to the people and leaders of the Islamic Republic of Iran, Obama said in a conciliatory tone that contrasted sharply with Bush's hard-line approach. We seek the promise of a new beginning.

Obama's willingness to talk to U.S. enemies like Iran has been welcomed internationally as a departure from what many saw as Bush's go-it-alone cowboy diplomacy epitomized by the 2003 U.S.-led invasion of Iraq.

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 United States is at loggerheads with Iran over its nuclear program, which Washington says is aimed at building atomic weapons, while Tehran insists it is for the peaceful generation of electricity.

Obama has also insisted that Iran end support for groups the United States considers terrorist organizations and cease bellicose language toward Israel, a close U.S. ally.

The United States cut off diplomatic ties with Iran during a 1979-1981 crisis, in which a group of militant Iranian students held 52 U.S. diplomats hostage at the American Embassy for 444 days.

Obama has said the United States is ready to extend a hand of peace to Iran if it unclenched its fist.

The Obama administration said recently it would invite Tehran to an international conference on Afghanistan later this month. Iran has said it would consider the invitation.

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