ANKARA - Pope Francis called for an end to all forms of fundamentalism on Friday and said fighting hunger and poverty, rather than military intervention alone, were key to stopping Islamist militants carrying out "grave persecutions" in Syria and Iraq.Speaking at the start of a three-day trip to Turkey, Francis said "terrorist violence" showed no sign of abating in Turkey's southern neighbors, where Islamist insurgents had declared a caliphate and persecuted Shi'ite Muslims, Christians and others who do not share their ultra-radical brand of Sunni Islam."It is licit, while always respecting international law, to stop an unjust aggressor," the leader of the world's 1.2 billion Roman Catholics said in reference to the Islamic State militants after a meeting with Turkish President Tayyip Erdogan."What is required is a concerted commitment on the part of all ... (to) enable resources to be directed, not to weaponry, but to the other noble battles worthy of man: the fight against hunger and sickness," he said.Before the meeting with Erdogan, Francis visited the tomb of Mustafa Kemal Ataturk, who founded the modern secular Turkish state in 1923.Francis faces a delicate mission in Turkey, a majority Muslim but constitutionally secular state, in strengthening ties with religious leaders while condemning violence against Christians and other minorities in the Middle East.Francis called for interreligious dialogue "so that there will be an end of all forms of fundamentalism and terrorism which gravely demean the dignity of every man and woman and exploit religion." Turkey has been a reluctant member of the US-led coalition against Islamic State, refusing a frontline military role but backing the Syrian opposition and calling for President Bashar Assad to be toppled.It is sheltering nearly 2 million refugees from Syria, thousands of Christians among them. Turkey has seen its own Christian population dwindle over the past century, with decades of violence and economic and political pressure forcing most Christians to leave after World War One and the emergence of the post-Ottoman Turkish state.Turkey's Christian population has dwindled over the past century and minority groups fear Erdogan's roots in Islamist politics mean it is moving in an ever less tolerant direction."It is essential that all citizens - Muslim, Jewish and Christian - both in the provision and practice of the law, enjoy the same rights and respect the same duties," Francis said.CHRISTIAN MIDDLE EAST EXODUSFrancis will travel to Istanbul on Saturday and meet Ecumenical Patriarch Bartholomew, spiritual head of 300 million Orthodox Christians worldwide, as part of an effort to forge closer ties between the ancient western and eastern wings of Christianity.Bartholomew's seat remains in Istanbul, a vestige of the Byzantine Empire, even as his flock in Turkey has dwindled to less than 3,000 among a population of 75 million Muslims.Syria's total Christian minority made up around 10 percent of the population of 22 million before its civil war began in 2011, while Iraq's Christian population has fallen by nearly 70 percent since the start of its 2003 war. The Turkey trip is the third by Francis to a mainly Muslim nation, after Jordan and Albania. Anagnostopoulos said Francis may pray inside Istanbul's Hagia Sophia, one of Christendom's greatest cathedrals for 900 years, one of Islam's greatest mosques for another 500, and now officially a museum.Such a move could upset some Muslims in Turkey, who would like to see it revived as a mosque.There was controversy over the venue for his meeting with Erdogan. Francis, renowned for his humble lifestyle, was the first guest in the president's lavish new 1,000-room palace. .Francis renounced the spacious papal apartments in the Vatican's Apostolic Palace and lives instead in a much more modest guest house in the Vatican.