This Ecumenical Press Service piece from December 12, 1963 gives an account of various reactions to Ecumenical Patriarch Anthenagoras' summit proposal. Jurisdictions included are the Vatican, the Melkite Greek Catholic Church, the Greek Orthodox Archdiocese of North and South America, the Church of Greece, and the Moscow Patriarchate.
The attached news article is courtesy of the Archives of the Greek Orthodox Archdiocese of America
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