Iranian Foreign Minister Manuchehr Mottaki addressed the participants, saying that Iran intends neither to confirm nor deny the Holocaust.
Drawing an implicit comparison with Western countries in which denying the Holocaust is a crime, Mottaki said the gathering provides a platform for open discussion of the topic and questioned a Europe "which claims to be free."
Iranian officials' assault on one of the most thoroughly documented campaigns of mass murder in history appears aimed at undermining the legitimacy of Israel and focusing attention on the Palestinian exodus.
Mottaki today challenged claimants that the Holocaust occurred to explain "why Palestinians should be made to pay for the crimes of the Nazis."
Israeli Foreign Ministry spokesman Mark Regev noted that such an approach flies in the face of international awareness and sensitivity to the tragedy.
"Unfortunately, the regime in Tehran has decided to give official sanction, official endorsement, to Holocaust denial," Regev said. "It was only last year that the UN General Assembly passed a resolution calling for an international day of remembrance and commemoration to the victims of the Holocaust and that resolution specifically condemned Holocaust denial."
The forum is organized by the Foreign Ministry's Institute for Political and International Studies (IPIS), which calls it a scientific forum to assess the magnitude of the Holocaust.
The conference was initiated by Iran's president, Mahmud Ahmadinejad, who has called the Holocaust "a myth."
Iran does not recognize the state of Israel, and Ahmadinejad has suggested that the Holocaust was invented to justify Israel's existence in the Middle East. He has also called for Israel to be "wiped from the map."
Municipal and national officials in Iran indirectly sponsored a recent cartoon contest on the Holocaust that was also condemned by many in the international community.
Reports claim that the participants will include a French professor who denies the existence of the gas chambers, Robert Faurisson; Austrian Holocaust revisionist Frederick Toeben; and a white supremacist and former Klu Klux Klan leader who once represented the southern U.S. state of Louisiana, David Duke.
Iranian media report that about 60 researchers from 30 countries will deliver speeches with titles like "Holocaust, Figures, Statistics, And Realities," "Historical Documents On The Holocaust," and "Nazism, Holocaust, And The Zionists."
The conference has been strongly condemned by Jewish groups, Western governments, and world leaders including British Prime Minister Tony Blair. Blair in January called news of an Iranian plan to host a "Holocaust denial" conference "shocking, ridiculous, and stupid."
The United States has also strongly criticized the conference, describing it as a "disgraceful act" by the Iranian government.
"As I understand it, this meeting is really focused on highlighting those people who deny that there was, in fact, a Holocaust," U.S. State department spokesman Sean McCormack told reporters on December 8.
Dujarric noted that the UN General Assembly passed a resolution in 2005 that "rejects any denial of the Holocaust as an historical event, either in full or [in] part."
Sadegh Zibakalam, a professor of political science at Tehran University, told RFE/RL that he thinks the event damages Iran's national interests and its international image.
"As an Iranian, I'm perplexed and astonished by the actions of our foreign ministry. I don't know what is the honor of gathering a group of anti-Semites, neo-Nazis, Ku Klux Klan members, and racists -- and bring them to Iran, for what?" Zibakalam said. "I don't understand what our establishment is trying to gain or to prove by doing this. And this is happening at a time when our nuclear case is at the UN and we have to do our best to gain the trust of the international community."
The only Jewish representative in Iran's parliament, Moris Motamed, was quoted by Reuters as saying that the conference has upset Iran's 25,000-strong Jewish community.
Iranian officials have dismissed suggestions that the event their country denies the crimes perpetrated by Adolf Hitler.
Foreign Minister Mottaki today called the Western criticism "predictable" and said the conference does not advocate anti-Semitism, which he described as unique to the West and unprecedented in Islamic countries.
Wolfgang Benz, a historian from the Center of Anti-Semitic Research in Berlin, said today that denial of the Holocaust reflects a current agenda for today, rather than a serious occupation with history:
"The Holocaust deniers know exactly what happened, they know about the scale of it, but they want to use the Holocaust for a different purpose," Benz said. "They want to articulate anti-Semitism against Israel and the Jews in the world to make an impression on the majority of people who are not informed and uneducated. It is all about politics, not about education or political correctness."
The "Jerusalem Post" reported today that an Israeli-Arab lawyer who runs a Holocaust museum in Nazareth was denied a visa to attend the conference. Khaled Muhammed, a lawyer, says he was denied entry to Iran after he sent a copy of his Israeli passport to the Iranian Embassy in Jordan.