"Any crime that happens in history against humanity, including the crime the Nazis created toward the Jews, is reprehensible and condemnable," the newly elected leader told CNN in an interview.
"Whatever criminality they committed against the Jews we condemn. The taking of human life is contemptible," he said yesterday, according to the US broadcaster's translation.
"It makes no difference whether that life is Christian, Jewish or Muslim. For us it is the same," added Rowhani, who gave his first speech at the United Nations General Assembly earlier yesterday.
The Holocaust "doesn't mean you can say Nazis committed crimes against a group so they must usurp the land of another group and occupy it," he said.
Rowhani was elected in June to succeed Mahmoud Ahmadinejad, who was a strident critic of Israel and questioned the Holocaust.
Ahmadinejad's remarks infuriated Israel, which has not ruled out military force against Iran's disputed nuclear program. The clerical state insists that its sensitive nuclear work is for peaceful purposes.