The US has also denied a visa to Iran's United Nations ambassador in Geneva to attend next week's General Assembly meeting because he was involved in the 1979 US hostage crisis, a UN official said.
Browne said Ahmadinejad had asked permission from the Port Authority of New York and New Jersey, US Secret Service and police department. The police and the Secret Service provide security to visiting heads of state.
The Port Authority, which owns the trade center site and is the only agency that could grant permission to go inside, said it attended a meeting with police regarding dignitary visits, not specifically about Ahmadinejad.
At that meeting, it was determined that no dignitaries would be allowed inside the site due to ongoing construction, said Steve Coleman, a Port Authority spokesman.
Mohammad Mir Ali Mohammadi, spokesman for the Iranian mission to the UN, said he was not notified officially that Ahmadinejad would not be allowed at the site, but said it was unfortunate.
"President Ahmadinejad intended to lay a wreath at the site of ground zero in order to pay tribute to the victims of the terrorists attack of September 11, 2001. We are hopeful that we can still work something out with the police department," he said.