Washington's decision followed intense lobbying by Israeli and Jewish groups.

In depth

 Geneva searches for the right words

The American Israel Public Affairs Committee said the decision "underscores America's unstinting commitment to combatting intolerance and racism in all its forms and in all settings".

The United States and Israel walked out of the World Conference on Racism in Durban, South Africa in 2001, after a row with some Muslim states about Israel's treatment of the Palestinians and anti-Semitism.

The five-day Geneva conference, which begins on Monday, has been called to assess international progress in fighting racism and xenophobia since the Durban meeting.

'Deeply dismayed'

Washington's decision is likely to anger human rights advocates and some in the African-American community who had hoped that Barack Obama, the nation's first black president, would send an official delegation.

"This decision is inconsistent with the administration's policy of engaging with those we agree with and those we disagree with"

Barbara Lee,
chair of the congressional black caucus

Barbara Lee, the Democrat chair of the congressional black caucus, said the group was "deeply dismayed".

"This decision is inconsistent with the administration's policy of engaging with those we agree with and those we disagree with," she said.

"By boycotting Durban, the US is making it more difficult for it to play a leadership role on UN Human Rights Council as it states it plans to do. This is a missed opportunity, plain and simple."

Some revisions had been made to the original text in order to find consensus, including the removal of passages specifically criticising Israel and others dealing with the defamation of religion.

But Wood said that not enough concessions had been made.

"[It] singles out one particular conflict and prejudges key issues that can only be resolved in negotiations between the Israelis and Palestinians," he said.

The US pulled out of planning talks for the Geneva meeting on February 27, complaining that changes must be made.

'Tragic farce'

Israel has criticised a meeting between Hans-Rudolf Merz, the Swiss president, and Mahmoud Ahmadinejad, his Iranian counterpart, to be held before the conference, which it described as a "tragic farce".

"Officially it is aimed at denouncing racism, but it has invited a Holocaust denier who has called for the destruction of Israel," Yossi Levy, an Israeli foreign ministry spokesman, said.

Australia, Canada, Italy and the Netherlands have also chosen not to attend.

"Regrettably, we cannot be confident that the review conference will not again be used as a platform to air offensive views, including anti-Semitic views," Stephen Smith, Australia's foreign minister, said.

The European Union is meeting late on Sunday to determine a common position on whether to send delegations to Geneva.

Britain has already said it would take part in the meeting but without a high-level official.