Ron Paul, one of the candidates vying for the Republican Party's presidential nomination, has met a representative from the extremist anti-Zionist group Neturei Karta.
Mr Paul, who has drawn criticism for a catalogue of controversial remarks about Israel and the Holocaust as well as race and homosexuality, shook hands with Rabbi Yisroel Dovid Weiss at an event in New Hampshire.
The Monsey rabbi, whose grandparents died in Auschwitz, has previously met Iranian leader Mahmoud Ahmadinejad at a conference questioning the Holocaust.
The controversial sect, rejected by almost every other part of the Jewish community, was founded in Jerusalem in 1938 in order to fight Zionism and has actively championed Israel's enemies ever since. One Neturei Karta member, Rabbi Moshe Hirsch, even served as Minister for Jewish Affairs in Yasir Arafat's Palestinian administration.
During the conversation Rabbi Weiss said that Judaism was a religion and "should never be transformed into a nationalism".
Mr Paul, who is staunchly against US aid to Israel, responded by saying that the suggestion was "good advice".
Mr Paul, a libertarian darling, came third in the Iowa caucus last week and is hoping to repeat his success at today's New Hampshire primary. Despite his popularity, experts have said it is unlikely he will win the nomination. The Republican Jewish Coalition banned Mr Paul from taking part in a recent Washington DC panel event with other presidential hopefuls, on the grounds that he was too far "outside of the mainstream".