White House spokesman Robert Gibbs on Friday condemned Iranian President Mahmoud Ahmadinejad's latest denial of the Holocaust.
"Obviously, we condemn what he said," Gibbs said at a news briefing. Such a comment "only serves to isolate Iran further from the world," he added.
Ahmadinejad delivered a speech at Tehran University, hinting once again that the Holocaust never took place: "If the Holocaust was planned by the West, why won't you allow any research on the Holocaust?
"The Holocaust," he added, "Has turned into a black box and they won't let anyone open it and examine it… If this is such an important event, why won't you let us reveal the reality to the entire world?"
Susan Rice, US ambassador to the United Nations, called Ahmadinejad's comments "hateful, adding Obama and Ahmadinejad un unlikely to "have a direct engagement" during the UN General Assembly in New York next week.
Britain was also swift to condemn Ahmadinejad's remarks, calling them "abhorrent as well as ignorant": "It is very important that the world community stands up against this tide of abuse. This outburst is not worthy of the leader of Iran," Foreign Secretary David Miliband said.
Germany's Foreign Minister Frank-Walter Steinmeier also condemned Ahmadinejad's remarks, calling Tehran's ruler "a disgrace to his country."
In a statement Steinmeier said: "Today's statements by the Iranian President are unacceptable. With his intolerable tirades he is a disgrace to his country. This sheer anti-Semitism demands our collective condemnation.
"We will continue to confront it decisively in the future."
Paris was next to issue a censure, with the French Foreign Ministry calling the Iranians president's speech "appalling and unacceptable."
Canadian Foreign Minister Lawrence Cannon deplored the speech as "irresponsible" and "full of anti-Semitic rhetoric." The Canadian government, he added, will not remain indifferent to that kind of rhetoric "by the radical Iranian regime which violates human rights."
The Associated Press contributed to this report