A Syrian refugee holds onto his children as he struggles to walk off a dinghy on the Greek island of Lesbos, after crossing a part of the Aegean Sea from Turkey to Lesbos September 24, 2015. REUTERS/Yannis Behrakis

Pope Francis addresses a joint meeting of the U.S. Congress as Vice President Joe Biden and Speaker of the House John Boehner look on in the House of Representatives Chamber on Capitol Hill in Washington, September 24, 2015. REUTERS/Kevin Lamarque

A Muslim girl touches the holy Kaaba at the Grand Mosque on the first day of Eid al-Adha during the annual haj pilgrimage in Mecca September 24, 2015. REUTERS/Ahmad Masood

Japan's Prime Minister Shinzo Abe, who is also the ruling Liberal Democratic Party leader, raises his arms as he shouts "Banzai" (or "Cheers") with his party lawmakers after he was re-elected as the party leader during the lawmakers' plenary meeting, at the party headquarters in Tokyo, September 24, 2015. REUTERS/Issei Kato

A Syrian migrant woman plays with her baby as she waits inside a vehicle to be allowed to continue their journey to Europe outside the Sarayici oil wrestling arena in Edirne, Turkey September 23, 2015. European Union leaders could promise billions of euros in new funding for Syrian refugees at an emergency summit on Wednesday where they will also try to patch up bitter divisions over the migration crisis. REUTERS/Yagiz Karahan

Two migrants carry a child in a pram as they walk towards the Hungarian border from Botovo, Croatia September 24, 2015. A trade war erupted between Serbia and Croatia on Thursday over the flow of migrants across their border, dragging relations between the ex-Yugoslav republics to their lowest ebb since the overthrow of late Serbian strongman Slobodan Milosevic in 2000. REUTERS/Antonio Bronic

A youth rides his tricycle on an empty street during the Jewish holiday of Yom Kippur September 23, 2015. Yom Kippur, or the Day of Atonement, is the holiest of Jewish holidays, when observant Jews atone for the sins of the past year. Traffic is not allowed during the 25-hour long period. REUTERS/Ammar Awad

Republican presidential candidate Donald Trump addresses the crowd at an event organised by the Greater Charleston Business Alliance and the South Carolina African American Chamber of Commerce in North Charleston, South Carolina, September 23, 2015. REUTERS/Randall Hill

A model backstagee is pictured before the Philipp Plein Spring/Summer 2016 collection during Milan Fashion Week in Italy September 23, 2015. REUTERS/Alessandro Garofalo

President Barack Obama shakes hands with Pope Francis during a welcoming ceremony at the White House in Washington September 23, 2015. REUTERS/Tony Gentile

Chinese President Xi Jinping visits with football players at Lincoln High School in Tacoma, Washington, September 23, 2015. Xi's busy stop on the West Coast is the first leg of a week-long trip to the United States and offers him a chance to highlight China's cooperation with U.S. companies before he heads to Washington. REUTERS/David Ryder

Muslim pilgrims pray on Mount Mercy on the plains of Arafat during the annual haj pilgrimage, outside the holy city of Mecca September 23, 2015. REUTERS/Ahmad Masood

Chinese First Lady Peng Liyuan visits Lincoln High School in Tacoma, Washington, September 23, 2015. REUTERS/David Ryder

Cuba's President Raul Castro (C) stands as Colombia's President Juan Manuel Santos (L) and FARC rebel leader Rodrigo Londono, better known by the nom de guerre Timochenko, shake hands in Havana, September 23, 2015. Colombian President Juan Manuel Santos and the top commander of leftist FARC rebels shook hands on Wednesday and agreed to reach a final peace agreement within six months in Latin America's longest war. ...more

Migrants wait to board buses on a field near the village of Babska, Croatia September 23, 2015. European Union leaders could promise billions of euros in new funding for Syrian refugees at an emergency summit where they will also try to patch up bitter divisions over the migration crisis. REUTERS/Marko Djurica

President Barack Obama stands with Pope Francis during an arrival ceremony for the pope at the White House in Washington September 23, 2015. The pontiff is on his first visit to the United States. REUTERS/Jonathan Ernst

A man, with his face injured, lies bleeding on the ground after being attacked on suspicion of snatching a mobile phone from a motorist shortly after a rally at Uhuru Park by opposition supporters in a show of solidarity with teachers currently engaged in a national striker over a pay increase dispute in capital Nairobi September 23, 2015. REUTERS/Noor Khamis

Japanese tourist pose for a photo with Peruvian anti-riot police in Lima's main square in down town Lima, September 23, 2015. REUTERS/Mariana Bazo

President Barack Obama sits with Pope Francis in the Oval Office as the pontiff is welcomed to the White House during a ceremony in Washington September 23, 2015. REUTERS/Tony Gentile

An eastern cottontail rabbit hides in the grass at Tommy Thompson Park located on a man-made peninsula known as the Leslie Street Spit, in Toronto June 24, 2015. It was created over 60 years ago by the dumping of dredged sand, concrete chunks and earth fill, expanding what was once just a thin strip of land in the city's busy harbor. An unexpected urban oasis, the development brings marshes, lagoons and forests to the centre of...more

A model backstage is pictured before the Philipp Plein Spring/Summer 2016 collection during Milan Fashion Week in Italy September 23, 2015. REUTERS/Alessandro Garofalo

A Syrian refugee carries his baby off an overcrowded dinghy after crossing part of the Aegean Sea from Turkey to the Greek island of Lesbos September 23, 2015. REUTERS/Yannis Behrakis

Pope Francis is touched by a nun as he arrives in the Basilica of the National Shrine of the Immaculate Conception for a Canonization Mass for Friar Junipero Serra in Washington September 23, 2015. REUTERS/Kevin Lamarque

A group of Sudanese and Eritrean migrants are seen in silhouette near a rock with white hand prints on the seawall at the Saint Ludovic border crossing on the Mediterranean Sea between Vintimiglia, Italy and Menton, France, September 23, 2015. European Union leaders meet in Brussels at an emergency summit on Wednesday to patch up bitter divisions over the migration crisis. REUTERS/Eric Gaillard

People crowd on top of a train entering the Dhaka airport rail station September 24, 2015, as thousands of Bangladeshi Muslims head home to celebrate Eid-al-Adha. Muslims across the world are celebrating the annual festival of Eid al-Adha also known as the Feast of the Sacrifice. REUTERS/Ashikur Rahman

Migrants carry an elderly woman as they walk on a field, after they crossed the border with Serbia, near Tovarnik, Croatia September 24, 2015. European Union leaders could promise billions of euros in new funding for Syrian refugees at an emergency summit where they will also try to patch up bitter divisions over the migration crisis. REUTERS/Marko Djurica

A migrant walks through a field towards the Hungarian border after arriving at the train station in Botovo, Croatia September 23, 2015. Hungarian leader Viktor Orban said on Wednesday he would propose that European Union states pay more into the EU budget to help cope with the refugee crisis and that Greece should allow other countries to defend its borders to slow the influx. REUTERS/Antonio Bronic