He says he will not accept a bad deal. He adds: "This deal will have my name on it."
Obama was speaking to Congregation Adas Israel in observance of Jewish American Heritage Month. The appearance coincides with Solidarity Shabbat, devoted to showing unity by political leaders in Europe and North America against anti-Semitism.
He sought to reassure the Jewish community that he shared Israel's commitment to Iran not obtaining a nuclear weapon.
But he says that doesn't mean there shouldn't be periodic disagreements between the governments of the US and Israel.