World leaders are gathering at United Nations headquarters in New York for the start of the annual UN General Assembly Debate.
Among the speakers scheduled to address the assembly on September 25 are U.S. President Barack Obama and French President Francois Hollande.
On the eve of the General Assembly, Iranian President Mahmud Ahmadinejad condemned the UN Security Council for protecting the "nuclear warheads" of Israel, thought to be the only Middle Eastern country to possess nuclear weapons although it refuses to disclose any capability.
Ahmadinejad's attack on Israel prompted a walkout of the Israeli delegation from the UN special session on the rule of law.
The Iranian leader also accused members of the Security Council of using the UN charter to justify remaining silent on an anti-Islam video that has sparked protests throughout the Muslim world.
"Divine prophets and heavenly religions which are the common heritage of mankind should be respected by the law in all societies, so that the conflicts leading to hatred, war and hostility between human beings will be avoided leading to peace and integration," Ahmadinejad said.
Earlier, Ahmadinejad told journalists Iran was ready to defend itself against any Israeli attack, adding that the Jewish state did not have "roots" in the Middle East and would be "eliminated."
UN Secretary-General Ban Ki-moon had warned Ahmadinejad of the dangers of incendiary rhetoric when two men met in New York on September 23.
Like Ahmadinejad, Ban also addressed the high-level UN meeting.
Ban said the rule of law should be used as the basis to peacefully resolve conflicts.
"The wider body of international law developed at the United Nations gives the international community a basis to cooperate and peacefully resolve conflicts and the means to ensure that there is no relapse of fighting. And with the development of accountability mechanisms, no war criminals should ever find safe harbor in the modern world," the UN leader said.
German Foreign Minister Guido Westerwelle, who is this month's Security Council president, said the Security Council must make sure sanctions are applied carefully.
"Sanctions remain an important tool in the maintenance and restoration of international peace and security," Westerwelle said. "The council has stressed the need to ensure that sanctions are carefully targeted in support of clear objectives and designed carefully so as to minimize possible adverse consequences and are implemented by member states. The council is committed to fair and clear procedures for placing individuals and entities on sanctions lists and for removing them as well, as for granting humanitarian exemptions."
Based on Reuters and AP reporting