(JTA) — A leader of the extremist anti-Zionist haredi Orthodox Neturei Karta sect who once met with former Iranian President Mahmoud Ahmadinejad has died. Rabbi Moshe Dov Ber Beck was 87.

Beck, a central leader of the Neturei Karta for decades, died Thursday night of complications of COVID following a long illness, according to the Israeli news site B’chadrei Charedim.

His anti-Zionist group was established in 1938 and opposes the modern state of Israel based on the belief that only God, at the time of the coming of the Messiah, can return the Jewish people to the land of Israel and reinstate Jewish sovereignty. The group has met with Holocaust deniers and leaders of the Iranian government, which has threatened Israel with extermination, even earning the condemnation of the leader of the Satmar Hasidic sect, also an anti-Zionist Orthodox group but less extreme.

In 2006, Neturei Karta participated in a Holocaust denial convention in Tehran. In 2008, Beck was among its leaders who met with Ahmadinejad in New York a day after the Iranian president made a speech at the United Nations that was widely condemned as anti-Semitic.

Beck, a native of Budapest, Hungary, moved to Israel as a boy in 1948. He eventually left Israel due to his anti-Zionist beliefs, moving to Montreal, Canada, and eventually to Monsey, New York, where he led a synagogue that served as a center for the Neturei Karta sect.