The University of Otago vice-chancellor was responding to comments from Otago Students for Justice in Palestine.
They claimed he was "running scared", but Mr Robertson said the decision was entirely out of his hands.
"The decision to not hold the lecture was made by the Arts Faculty. It was not made by me.
"My understanding, and you could talk to them, is they made that decision because they felt that it was highly likely in the environment of the campus yesterday that we wouldn’t have been able to air both the issues around Palestine and my lecture in a constructive way.
"And so they made that decision. That was not my decision."
The lecture would take place sometime early next year, he said.
"I’m an arts graduate of this university and I believe in the world that we’re in and moving into the place of the arts is very significant, particularly in an era where AI is going to do a lot more things for and with us.
"How do we make sure that we maintain the human side of that? And that’s the essence of the arts. So I was going to talk about the way in which the arts can provide some of the answers to the big challenges in the world; the way we need to get a more cross-discipline approach to what we do."
• On Monday, Grant Robertson looks back on his first 100 days as vice-chancellor.
