Iranian President Mahmoud Ahmadinejad's scheduled visit to New York next week has triggered a controversy, with the city denying his request to tour the site of the destroyed World Trade Center [Images] and angry reactions coming in over his plans to speak at a premier university.

A report from Tehran said Ahmadinejad, who is arriving in New York on Sunday and will address the UN General Assembly on Tuesday, will not press for visiting Ground Zero to pay homage to 9/11 victims after the authorities denied permission to him citing ongoing construction and security concerns.

Besides addressing the 192-member Assembly, Ahmadinejad is scheduled to participate in a question-and-answer session with students and faculty members of the prestigious Columbia University as a part of the World Leaders Forum.

Columbia University's decision came under attack from City Council speaker Christine Quinn who shot off a letter to the institution, saying the idea of Ahmadinejad as an honoured guest anywhere in the city is "offensive to all New Yorkers."

Ahmadinejad is a "holocaust-denier" who is here to spread his "hate-mongering," Quinn alleged.

Republican presidential hopeful John McCain accused the Iranian president of helping insurgents in Iraq attack US troops and said he should not be given an invitation to speak at an American university.

But the university's president Lee Bollinger defended the invitation, citing its "long-standing" tradition of serving as a "major forum for robust debate, especially (on) global issues." Bollinger said Ahmadinejad has agreed to answer questions on Israel and the holocaust.

"He (Ahmadinejad) can say whatever he wants on any street corner, but should not be given centrestage at one of New York's most prestigious centres of high education," Quinn said.

Last year, the university had cancelled plans for a speech by him, citing security and logistic concerns after it came under fire especially from Jewish Defence Organisation.

City officials say they had decided to allow no dignitary to visit the WTC site as construction is going on.

"The workers are laying the foundations and it would not be possible for the Iranian president to go where other people cannot go," Police Commissioner Raymond Kelly said.

President George W Bush [Images] backed the decision, saying, "I can understand why they would not want somebody running a country who is the state sponsor of terror down at the site."

"It is appalling that President Ahmadinejad, one of the world's leading sponsors of terror, would find it appropriate to visit this hallowed ground," State Department spokesman Tom Casey was quoted as saying by CNN.

Democratic presidential front-runner Hillary Clinton said it is "unacceptable" for Ahmadinejad, who refuses to renounce his own country's support of terrorism, to visit the site.

There had been demands by some hardline Republicans that Ahmadinejad should not be given visa to visit the United States to address the Assembly and that Secretary-General Ban Ki-moon should withdraw the invitation sent to him.

But Ban rejected the demand, saying all member states have the right to address the Assembly and choose who would address it.

The United States does not have diplomatic relations with Iran. America considers the country as a sponsor of terrorism and accuses it of meddling in the Affairs of Iraq where the government, like in Iran, is led by Shiites.