UNITED NATIONS -- President Barack Obama took sharp aim at Iran from the UN podium Tuesday, saying the "time and space" to resolve the protracted impasse over Iran's nuclear ambitions through diplomacy is "not unlimited."
"Make no mistake," Obama said to delegates in a half-hour speech at the General Assembly. "A nuclear-armed Iran is not a challenge that can be contained. It would threaten the elimination of Israel, the security of Gulf nations and the stability of the global economy. . . . That's why the United States will do what we must to prevent Iran from obtaining a nuclear weapon."
The warning came a few weeks after he was asked by Israeli Prime Minister Benjamin Netanyahu to draw a "red line" on Iran's nuclear program -- a limit that, if crossed by Iran, would trigger a U.S. military response. Obama did not spell out Tuesday where that point would be.
Obama scolded Iran because it "continues to prop up a dictator in Damascus," referring to Syrian President Bashar Assad, whose government's crackdown on dissidents has devolved into a civil war that UN officials said has left 19,000 people dead since March 2011.
His remarks came a day before Iran's president, Mahmoud Ahmadinejad, is scheduled to speak, and two days before Netanyahu. On Monday, Ahmadinejad all but scoffed at the prospect that Israel would attack it for developing a nuclear weapon. Ahmadinejad did not attend Obama's speech.
In the wide-ranging speech, Obama also:
Denounced the wave of anti-U.S. violence in the Muslim world sparked by an anti-Islamic film.
"The attacks of the last two weeks are not simply an assault on America," he said. "They're also an assault on the very ideals upon which the UN was founded."
Extolled freedom of speech in the United States even while denouncing as "crude and disgusting" the anti-Muslim video believed to have sparked the demonstration and later attack that killed U.S. Ambassador Chris Stevens.
"Here in the United States, countless publications provoke offense. Like me, the majority of Americans are Christian and we do not ban blasphemy of our most sacred beliefs. As president of our country and commander of our military, I accept that people are going to call me awful things every day -- and I will always defend their right to do so," he said.
Said diplomacy and tolerance were keys to ending the Israeli-Palestinian conflict.
"Among Israelis and Palestinians, the future must not belong to those who turn their backs on a prospect of peace," he said. "Let us leave behind those who thrive on conflict, those who reject the right of Israel to exist. The road is hard, but the destination is clear -- a secure, Jewish state of Israel and an independent, prosperous Palestine," he said.
Obama's speech drew splashes of applause as it touched on the spread of democratic practices.
Syria's crisis is dominating the annual gathering of world leaders. UN Secretary-General Ban Ki-moon opened the debate and called the current state of Syria "a regional calamity with global ramifications."