Terming the US offer of talks on Iran's controversial nuclear programme a "historic opportunity", President George W Bush on Monday warned Tehran of "progressively stronger political and economic sanctions" if it failed to voluntarily suspend nuclear enrichment.
Speaking at the United States Merchant Marine Academy in New York, Bush said "Iran's leaders have a clear choice. We hope they will accept our offer and voluntarily suspend these activities, so we can work out an agreement that will bring Iran real benefits.
"If Iran's leaders reject our offer, it will result in action before the Security Council, further isolation from the world, and progressively stronger political and economic sanctions" Bush said.
"We have presented a reasonable offer. Iran's leaders should see our proposal for what it is - a historic opportunity to set their country on a better course.
"If Iran's leaders want peace and prosperity and a more hopeful future for their people, they should accept our offer, abandon any ambitions to obtain nuclear weapons, and come into compliance with their international obligations" he said.
Launching a scathing attack on the Iranian regime, he alleged that "nuclear weapons in the hands of this regime would be a grave threat to people everywhere."
"And by pursuing nuclear activities that mask its effort to acquire nuclear weapons, the regime is acting in defiance of its treaty obligations, of the United Nations Security Council, and of the International Atomic Energy Agency," Bush said.
"I've discussed the problem of the Iranian regime extensively with leaders in Europe, particularly in Great Britain and Germany and France. I've also consulted closely with the Presidents of Russia and China. We've all agreed on a unified approach to solve this problem diplomatically," he said.
The United States has offered to come to the table with its partners and meet with Iran's representatives - as soon as the Iranian regime fully and verifiably suspends its uranium enrichment and reprocessing activities, he remarked to the graduating class.
In a message to the people of Iran, the President said Washington had no grouse against them. "The United States respects you and your country. We admire your rich history, your vibrant culture, and your many contributions to civilization," he said.
He, however, said the Iranians have a legitimate desire to make greater progress including the development of civilian nuclear energy.
"This is a legitimate desire. We believe the Iranian people should enjoy the benefits of a truly peaceful programme to use nuclear reactors to generate electric power. So America supports the Iranian people's rights to develop nuclear energy peacefully, with proper international safeguards," he said.