Cameramen and photographers take pictures as an Iranian technician walks through the Uranium Conversion Facility just outside the city of Isfahan in 2007.

Cameramen and photographers take pictures as an Iranian technician walks through the Uranium Conversion Facility just outside the city of Isfahan in 2007. Vahid Salemi/AP file photo

Obama: U.S. will 'do what we must' to stop a nuclear Iran

Report finds Iran's rate of uranium enrichment has nearly tripled since Obama took office.

In a speech to the United Nations General Assembly on Tuesday, President Obama will say the U.S. will “do what we must” to prevent the Iranian government from securing a nuclear weapon, the Associated Press reported.

“Make no mistake: a nuclear-armed Iran is not a challenge that can be contained,” Obama says in prepared remarks, in what may be his final international address before the election, according to the AP, adding, “That is why a coalition of countries is holding the Iranian government accountable. And that is why the United States will do what we must to prevent Iran from obtaining a nuclear weapon.”

Israeli Prime Minister Benjamin Netanyahu has pressured the Obama administration to join his country in drawing a “red line” for Iran on it's nuclear program. Although the president has said that Israel is one of America’s closest allies in the region, Republican presidential nominee Mitt Romney has been critical of Obama’s commitment.

Obama’s resolve in preventing a nuclear weapon comes as the rate of uranium enrichment has nearly tripled in Iran since Obama took office, The Washington Post reports.

The president will also challenge world leaders to confront the root causes of the anger that sprung from an anti-Islamic video produced in the U.S., which sparked violent protests across the Muslim world. In his speech, the president says there is a choice “between the forces that would drive us apart and the hopes we hold in common,” according to the AP.

Although recognizing the violence in the region, including the deaths of the U.S. ambassador to Libya and three other Americans, Obama will reaffirm the U.S. commitment to transitioning democracies in the region. In an interview with CBS’s 60 Minutes recently, the president called the violence “bumps in the road,” which has also been criticized by his Republican opponent.

Former British Prime Minister Tony Blair defended Obama on Tuesday, however, saying there is bound to be violence in the region during times of transition. Blair said the president's "approach is right," by supporting movements for democracy and change in the region.

“I think, as your president's been saying, long-term this will work out. Short-term, it's going to be tough” Blair said on MSNBC’s Morning Joe. “But we've got to hang in there and actually support those people who are trying to reach for a better form of life and the type of democracy and the type of values we believe in.”

Obama has also been attacked in recent days for not taking any private meetings with world leaders during the U.N. confab. “This is time for a president who will shape events in the Middle East, not just be merciful or be at the mercy of the events,” Romney said at a campaign event on Monday. White House press secretary Jay Carney called the comments “profoundly offensive.”