U.S. President Barack Obama will discuss recent violence in the Middle East and the Iranian nuclear standoff when he addresses the United Nations General Assembly Tuesday.

In excerpts of his speech issued by the White House, the president denounces the violence that spread across the Muslim world over a crudely made video that mocked the Prophet Muhammad. The violence included an attack on the U.S. consulate in Benghazi that led to the deaths of U.S. Ambassador to Libya Christopher Stevens and three U.S. diplomatic officers.

Mr. Obama will tell the U.N. delegates the attacks on the U.S. diplomatic outposts in Libya and elsewhere were “an assault on the very ideals upon which the United Nations was founded.”

He warns Iran that while there is “still time and space” to negotiate over its nuclear program, “that time is not unlimited.” He stresses that the United States will do all it can “to prevent Iran from obtaining a nuclear weapon.”

The president also plans to say that the United States will never retreat from the world and will stand strongly for democratic values.

Syria will likely dominate this year's U.N. General Assembly session. The world is deadlocked on how to deal with that country's conflict, which has killed more than 20,000 people, mostly civilians. Russia and China have vetoed tough sanctions against the Syrian government in the Security Council, and the United States has expressed no desire for direct military intervention.

More than 120 world leaders will attend the General Assembly meeting to discuss and debate wars, political crises and humanitarian concerns.