Iranian President Mahmoud Ahmadinejad failed to address concerns his country has not met its obligations under a key nuclear treaty during a speech at the United Nations on Monday, the White House said.
Ahmadinejad "failed to speak about the obligations that it won't live up to," spokesman Robert Gibbs said as a five-year review of the nuclear Non-Proliferation Treaty began in New York, DPA reported.
"Those that are involved in the NPT conference and are living up to their obligations would have wanted to hear the Iranians discuss wanting to live up to their obligations," Gibbs added.
Ahmadinejad was the only leader to speak at the opening day of the gathering, and used the opportunity to accuse countries with nuclear arms of seeking to impose their will on nations without atomic weapons, prompting the US delegation to exit the UN General Assembly.
Gibbs said the US representatives walked out "as wild accusations were made during the speech."
The United States and its European allies are pushing for another round of UN Security Council sanctions against Tehran over suspicions it's using a nuclear energy programme to develop a weapons capability.
Ahmadinejad reiterated his country's position that its nuclear activities are limited to purely peaceful goals.
US Secretary of State Hillary Rodham Clinton was expected to hold meetings with other diplomats hoping to win support for international sanctions.