The dean of Harvard University's John F. Kennedy School of Government defended the decision to invite former Iranian President Mohammad Khatami to speak on the eve of the anniversary of the Sept. 11 terror attacks.

"Do we listen to those that we disagree with, and vigorously challenge them, or do we close our ears completely?" Dean David Ellwood said in an interview published Thursday in The Boston Globe.

Ellwood said he approved the invitation, first proposed by faculty after they learned Khatami would be speaking at the United Nations.

Sept. 10 was the only date available, the dean said.

He also emphasized that Khatami would not be allowed to visit unless he was willing to take unscripted questions.

Harvard has been criticized for the timing of its invitation to Khatami, who is in the middle of a two-week tour of the United States. Khatami already has spoken in Chicago and at the United Nations and will attend two Islamic conferences as well as deliver a speech at the National Cathedral in Washington.

Khatami is the most senior Iranian to travel outside New York in the United States since Islamic fundamentalists seized the U.S. Embassy in Tehran in 1979 and held Americans hostage for 444 days.

On Saturday, Khatami spoke in the Chicago area and said that U.S. foreign policy triggers terrorism and violence in the world, but American Muslims can play a key role in promoting peace and security.

The timing of Khatami's visit to Harvard has been denounced in the Boston Herald and the New York Sun, which ran a front page editorial.

"The John F. Kennedy School of Government at Harvard University, fresh from having established itself as a headwater of anti-Israel agitation, is choosing to mark the fifth anniversary of the terrorist attacks in an astounding way by hosting Mohammed Khatemi, a former president of Iran, an enemy state levying a terrorist war against America," the Sun wrote. "Mr. Khatemi has been invited to speak on, of all things, "Ethics of Tolerance in the Age of Violence."

Several months ago Harvard came under attack when a professor helped write an article criticizing a so-called "Israel Lobby" for driving foreign policy in Washington to the detriment of U.S. interests. In 2004, Harvard returned a $2.5 million gift to the Divinity School from the president of the United Arab Emirates, after controversy arose over the president's ties to a think tank espousing anti-Semitic ideas.

On Wednesday, a Boston-area Jewish group condemned Khatami's scheduled visit.

"As an alum, I'm personally offended," said Nancy K. Kaufman, executive director of the Jewish Community Relations Council of Greater Boston, who has a master's degree from the Kennedy School. "We believe in freedom of speech, but I really question the judgment of Harvard giving him a platform."