President Barack Obama yesterday condemned as hateful, offensive and inexcusable a suggestion by Iranian President Mahmoud Ahmadinejad of a US government role in the September 11, 2001, attacks on the United States.
Mr Ahmadinejad also said there may be a meeting next month on his country's disputed nuclear program.
Mr Obama, in an interview with the BBC's Persian news service, lashed out at Mr Ahmadinejad for the latest of what the White House called a long list of outrageous comments that would deepen Tehran's international isolation.
"It was offensive. It was hateful," Mr Obama said, according to interview excerpts released by the White House. "And particularly for him to make the statement here in Manhattan, just a little north of Ground Zero, where families lost their loved ones ... for him to make a statement like that was inexcusable."
The United States and its Western allies are locked in a standoff with Iran over its nuclear program.
Mr Obama agreed to the BBC interview before Mr Ahmadinejad made his comments, as a way of speaking direct to the Iranian people.
Mr Ahmadinejad, in an address at the United Nations General Assembly on Thursday, said it was mostly US government officials and statesmen who believed al-Qa'ida militants carried out the plane hijackings and suicide attacks on New York and Washington.