 While in this position he attended the Second Vatican Council where, as a representative of the Melkite Church, he worked with Patriarch Maximos IV to further understanding and cooperation between the Church of Rome and the Eastern Orthodox Church.In November 1967 Patriarch Maximos IV was succeeded after his death by Archbishop Tawil's friend and predecessor in the Cairo Patriarchal College, Archbishop George Selim Hakim, a native Egyptian who took the name Maximos V. Archbishop Hakim had been the first Archbishop of Nazareth and all Galilee and had been the guide for Pope Paul VI on his pilgrimage to the Holy Land at the beginning of his reign.On October 30, 1969, Archbishop Tawil was appointed Apostolic Exarch for the United States by Pope Paul VI, and was installed on March 15, 1970.