Delegates to a United Nations conference on nuclear proliferation walked out as Mahmoud Ahmadinejad began his speech, which attacked the United States and Israel.

Ahmadinejad used his opening speech at the Non-Proliferation Treaty Review conference to parry attacks from an increasingly frustrated international community and to highlight what he deemed the hypocrisy of the United States and Israel.

As the Iranian president delivered his speech, several protests took place outside the U.N.'s New York headquarters.

One protest featured several members of the U.S. Congress, New York state senators and Jewish leaders gathered across the street from the U.N. building to denounce Ahmadinejad’s presence at the conference.

Speaking from the podium of the General Assembly Hall, U.S. Secretary of State Hillary Clinton accused Iran of "flouting the rules" of the Nuclear Nonproliferation Treaty with its suspect uranium enrichment program, and said it is "time for a strong international response."