The Most Reverend Justin Welby told Egyptian Christian leaders on the first day of his visit to Egypt and the Holy Land that "the prayers and solidarity of the Anglican Communion" are with them.
The Archbishop met His Holiness Pope Tawadros II, the head of the Coptic Orthodox Church, and the Grand Imam of Al-Azhar, Sheikh Mohamed Ahmed el-Tayeb.
In his meeting with Pope Tawadros II in Cairo, Archbishop Welby spoke of how the Church can "flourish and grow" whatever the challenges it faces.
The meeting was joined by several senior Orthodox leaders, including Bishop Angaelos, General Bishop of the Coptic Orthodox Church in the UK.
Archbishop Welby and Pope Tawadros II spoke of their "delight" that official theological dialogue aimed at visible unity and witness was again a part of Anglican-Oriental Orthodox relations.
They acknowledged the resumption in the UK later this year of the Anglican Oriental Orthodox International Theological Commission, which will be reflecting on the work of the Holy Spirit in the life of the Church. The commission has previously agreed a statement on the person of Jesus Christ.
Thanking the Archbishop for travelling to Cairo, Pope Tawadros said: "We must build our dialogue and studies on love and crown them with prayers; we must also prepare our people to love, accept and work with each other in the spirit of unity found in John 17."
Archbishop Welby described the meeting as "warm and joyful".
He said: "We had a very wide-ranging discussion, coming back several times to the question of how the Church can flourish and grow in prayer, in love for one another and in teaching of the scriptures to our contemporaries. It's important that we find a way of enabling our affection for one another to be transformed into effective shared witness."
Archbishop Welby added that he "had the opportunity to express the prayer and solidarity of the Anglican Communion with all the Christians of the Middle East as they seek the common good of their various nations".
Meeting with the Grand Imam, also in Cairo, the two leaders affirmed the importance of continued dialogue between the Anglican Communion and Al-Azhar during a critical time for Egypt and the wider region.
Archbishop Welby described the Grand Imam as "committed" and "extremely good at" interfaith dialogue, with a "deep concern for all the people of the region, whatever their background".
He expressed appreciation for the way in which the Grand Imam and Al-Azhar had spoken up for the rights of all people in Egypt.
The Archbishop is paying a five-day visit to the region at the invitation of the Most Reverend Mouneer Anis, President Bishop of the Episcopal Church in Jerusalem and the Middle East.
Bishop Anis, the Coptic Church, other local churches and Al-Azhar are collaborating on a series of inter-religious workshops that bring together imams and priests from places that have experienced inter-religious tension and violence.
Archbishop Welby told of his recent meeting with Sheikh Ibrahim Mogra of the Muslim Council of Britain to demonstrate their solidarity after the murder of Drummer Lee Rigby in Woolwich.
"I have been enormously inspired to spend time with Bishop Mouneer and to see something of his loving ministry here in Cairo and across the Province," said Archbishop Welby.
"His Christ-centred leadership provides great encouragement amid the many challenges faced across the region, while his generous leadership of the Global South offers much hope for the Anglican Communion."
