NEW YORK — Columbia University President Lee Bollinger publicly defended his incisive introduction of Iranian President Mahmoud Ahmadinejad on Wednesday.

Bollinger’s speech, in which he referred to Ahmadinejad as a “petty and cruel dictator,” has drawn both praise for its forcefulness and criticism from some who feel it went too far and was disrespectful of an invited guest.

“I believe very strongly that this is free speech at its best,” Bollinger said of Monday’s World Leaders Forum event.

“The norm of civility which we all love can make it very difficult in a context such as this to lay out fully the disagreement,” he said in response to reporters’ questions at a press conference regarding the University’s proposed expansion into Manhattanville. “These are not small matters, questioning or denying the Holocaust … [and] making threats against the state of Israel. … You need to have an opportunity in a true exchange to express as fully as you possibly can with as much emotion as is required.”

Bollinger said that the tone of his introduction was not a response to public criticism of Ahmadinejad’s invitation to Columbia, noting that he made clear in his first statement about the invitation that he would introduce the Iranian with a series of tough questions on his views on the Holocaust, Israel, and Iran’s nuclear program.

“We said explicitly that it would involve very sharp questions and statements,” he said. “The statements I made had nothing to do with responding to those objections [to the invitation]. This was my effort to address as fully and deeply as I can my sense of what this man has stood for.”