Republican vice presidential candidate Sarah Palin told supporters Friday that Democrat partisans had pressured organizers of an anti-Iran rally in New York next week to withdraw an invitation for her to appear.

"This should be an issue that unites all Americans. Iran should not be allowed to acquire nuclear weapons, period," Palin said. "Unfortunately, some Democrat partisans put politics first and now no elected official can appear. This should not be a matter of partisan politics."

Republican presidential candidate John McCain accused organizers on Thursday of withdrawing Palin's invitation under pressure from her Democratic rivals, a charge that Barack Obama's campaign vehemently denies.

Obama spokesman Tommy Vietor batted away the suggestion, saying they had planned to send Democratic Rep. Robert Wexler to attend the rally on the campaign's behalf and did nothing to discourage Palin's attendance.

"Israel needs real leadership to stop Iran, not phony political controversies," Vietor said.

A group of Jewish organizations had invited both Palin and former Democratic presidential candidate Sen. Hillary Clinton to speak at the protest, to be held near the United Nations on Monday against Iranian President Mahmoud Ahmadinejad.

Ahmadinejad has made countless comments against the state of Israel, including that it should be wiped off the map.

But a senior Clinton adviser said the New York Democrat canceled her appearance after learning Palin was scheduled to address demonstrators as well.

"Gov. Palin was pleased to accept an invitation to address this rally and show her resolve on this grave national security issue, regrettably that invitation has since been withdrawn under pressure from Democratic partisans," McCain said in a statement.

"We stand shoulder to shoulder with Republicans, Democrats and independents alike to oppose Ahmadinejad's goal of a nuclear armed Iran," he said. "Sen. Obama's campaign had the opportunity to join us. Sen. Obama chose politics rather than the national interest."

The suggestion that Democrats urged rally organizers to disinvite Palin "is totally false," said Daniel Shapiro, a spokesman for the Obama campaign. "We never pressured anyone to do anything with Gov. Palin."

Shapiro said the Obama campaign offered to send Democratic Rep. Robert Wexler, a top Jewish surrogate, to the rally.

Clinton decided not to attend because she did not want to take part in a "partisan political event," her aide said. She lost a hard-fought battle for her party's nomination to Obama, but is now supporting the Democratic nominee for the November 4 U.S. presidential election.

Among those scheduled to attend the protest are Nobel laureate Elie Wiesel and Speaker of the Knesset Dalia Itzik, publicist Casey Sanders said on behalf of the organizers.

"In order to keep the focus on Iranian threats and to ensure that this critical message not be obscured, the organizers of the rally have decided not to have any American political personalities appear," Sanders said.

UN officials have also said it was possible McCain and Palin might show up on the sidelines of the opening of the UN General Assembly on Tuesday.

This would give Palin a chance to meet a few world leaders on the day U.S. President George W. Bush and one of his main foes, Iranian President Ahmadinejad, address the 192 UN member states.

Although Palin, 44, has brought new energy to the McCain campaign and helped narrow Obama's lead in opinion polls before the election, Democrats say the mother of five lacks the foreign policy experience a vice president should have.

Iran denies Western allegations that it is seeking atomic weapons, but has refused to suspend sensitive parts of its nuclear program that could be used to make atom bomb fuel.