Pope Francis has called for an interfaith effort to counter extremism in a key speech at the start of his visit to Turkey.
He gave a speech in Ankara where he said the Middle East had "for too long been a theatre of fratricidal wars".
The pontiff's visit will last three days and is only the fourth time a pope has visit Muslim-majority Turkey. His trip comes as the Islamic State (IS) continue to fight to gain land in Syria near the Turkish border.
In his speech, he said: "Fanaticism and fundamentalism, as well as irrational fears which foster misunderstanding and discrimination, need to be countered by the solidarity of all believers.
"Inter-religious and intercultural dialogue can make an important contribution to attaining this lofty and urgent goal, so that there will be an end to all forms of fundamentalism and terrorism which gravely demean the dignity of every man and woman and exploit religion.
"In addition to providing much-needed assistance and humanitarian aid, we cannot remain indifferent to the causes of these tragedies," he said, in reference to the Syrian civil war and turmoil in Iraq.
Turkish President Tayyip Recep Erdogan said the Pope's visit was a "very significant and very crucial step which will enhance the hopes of peace in our region".
He said: "Racism and Islamophobia in the West and violence and terrorism in Islamic lands make it important that we come together and co-operate."
Francis became the first foreign world figure to visit Erdogan's new 1,000 room presidential palace in Ankara.
Turkey holds a population of 120,000 Christians among 80 million citizens, the majority being Muslim.