Iranian President Mahmoud Ahmadinejad will attend a U.N. anti-racism conference starting in Geneva next week, the United Nations said Tuesday.

The addition of Ahmadinejad to the speakers adds to fears by some Western countries that the conference could be diverted by Muslim countries into a verbal attack on Israel.

Ahmadinejad has repeatedly called for the destruction of Israel and questioned whether the Holocaust occurred.

The conference will be held April 20-25. At least 35 nations have confirmed participation, U.N. spokeswoman Marie Heuze said.

U.N. Secretary-General Ban Ki-moon and the head of the Organization of The Islamic Conference, Ekmeleddin Ihsanoglu, will also take part in the opening of the meeting, Heuze said.

But Western countries have been reluctant to commit themselves until they have a better idea of what the conference is setting out to do.

Israel and Canada have already said they won't attend the conference over concerns about a possible repeat of verbal attacks on Israel that marred the first such meeting in Durban, South Africa, eight years ago.

The U.S. and European countries have threatened to stay away from the latest meeting, also called "Durban II," if Muslim countries turn it into an attack on Israel and on free speech that criticizes Islam.

The U.S. State Department said Monday it was pleased by a diplomatic push to revise a draft document that is expected to be approved by the conference and suggested it could attend the meeting if the efforts succeed.

Informal negotiations last week brought some progress to the text, but consensus had yet to be reached on the issues of incitement to religious hatred and on free speech.

Another round of negotiations scheduled to start Tuesday would be decisive, European diplomats said.

"If by the end of this week we have a good result as far as the text is concerned, we can participate," a European diplomat said on condition of anonymity because the EU had yet to determine its final position.

The U.S. and Israel walked out midway through the 2001 conference over a draft resolution that singled out Israel for criticism and likened Zionism -- the movement to establish and maintain a Jewish state -- to racism. The European Union also refused to accept demands by Arab states to criticize Israel for its "racist practices."

In the end, the 2001 conference dropped criticism of Israel. It urged governments to take concrete steps to fight discrimination and recognized the plight of the Palestinian people and the need for Israel to have security.