Mr. Rouhani, who has energetically sought to differentiate himself from Mahmoud Ahmadinejad, his predecessor who was known for bombastic anti-Semitic rants that included Holocaust denial, said in American television interviews on Tuesday and Wednesday that he considered the Nazi mass murder of Jews reprehensible. But he immediately added that the Nazis had killed many people, not just Jews, which was also reprehensible. He also said that the consequence of the Holocaust should not have been the displacement of Palestinians from their lands — a reference to Israel.

While Mr. Rouhani may have succeeded in at least acknowledging and condemning the Holocaust, a subject that resonates with Jews and others around the world, his words did little to advance his publicly stated message of friendship. If anything the ambiguously translated language of his condemnation — which was challenged by some in Iran, including the Fars News Agency, run by the Revolutionary Guards — only seemed to entangle him in a dispute he had hoped to avoid.

Mr. Rouhani seemed to dilute his condemnation on Thursday at a forum sponsored by the Council on Foreign Relations and the Asia Society in New York. Asked if he could clarify his stand on the Holocaust, he said through a translator that he believed he had responded to that question in earlier interviews. “We condemn the crimes by the Nazis during World War II,” he said, but added that many people were killed, including “a group of Jewish people.” This did not mean, he said, “that anybody else should have to pay for those crimes.”