 Koch headed the Vatican's delegation to Istanbul, Turkey to the Ecumenical Patriarch of Constantinople, Patriarch Bartholomew I, for the Feast of Saint Andrew the Apostle on 30 November 2010 (the Patriarchate sends a delegation each year in turn for the Solemnity of the Holy Apostles Saint Peter and Saint Paul on 29 June).He co-presided over a meeting of the Joint International Commission for Theological Dialogue Between the Catholic Church and the Orthodox Church in Vienna, Austria in September 2010 with Metropolitan John Zizioulas of Pergamon.On 4 May 2011 Pope Benedict appointed Koch a member of the Congregation for the Causes of Saints.