This year more than 4 million people have fled Syria, and at least 7.6 million more are displaced within the country. The refugee crisis is said to be the worst since World War II.
A Frontex helicopter patrols over a Syrian child who has just arrived at a beach on the Greek island of Lesbos, Aug. 10, 2015. Thousands of people are stranded on Greek islands, waiting for temporary documents before continuing their travel to northern Europe.
Refugees sleep near the main bus station in Istanbul, Turkey, Sept. 15, 2015.
Yasmine, a 6-year-old from Deir Al Zour, Syria, cries at the beach after arriving at Lesbos, Sept. 11, 2015. Yasmine said the dress her grandmother gave her had been thrown away by the men who brought her family here across the narrow sea from Bodrum, Turkey. The crossing from Turkey and the eventual trip to Athens is only the beginning for Yasmine's and other families.
A Syrian refugee cries as she carries her baby through the mud to cross the border from Greece into Macedonia during a rainstorm, near the Greek village of Idomeni, Sept. 10, 2015.
A Syrian refugee rests after arriving at a Lesbos beach onboard a raft during a rainstorm, Oct. 22, 2015. The rate of arrivals had risen in a rush to beat the onset of freezing winter.
A group of refugees protect themselves from the weather with emergency blankets as they huddle on the sea wall at the Saint Ludovic border crossing on the Mediterranean Sea between Vintimille, Italy, and Menton, France, June 14, 2015.
A refugee breaks out of a holding area and runs away from police in Roszke, Hungary, Sept. 8, 2015.
A Syrian refugee holds on to his children as he struggles to walk off a dinghy into Lesbos after crossing the Aegean Sea from Turkey, Sept. 24, 2015.
Hanine (left), 3, is hugged by her grandmother, and Yasmine, 6, by her aunt upon their arrival in Lubeck, Germany, Sept. 18, 2015.
A local man helps a Syrian refugee swimming exhaustedly from a dinghy to a Lesbos beach, Sept. 17, 2015.
A mounted police officer leads a group of refugees near Dobova, Slovenia, Oct. 20, 2015.
Four-year-old Rashida from Kobani, Syria, part of a new group of more than a thousand refugees, sleeps as they wait at the border of Macedonia and Greece to enter into Macedonia, Aug. 20, 2015.
A volunteer carries a young boy on to Lesbos after a boat of refugees sank while crossing from Turkey, causing multiple fatalities, Oct. 28, 2015.
Syrian refugees arrive on the shores of Lesbos in an inflatable boat from Turkey, Aug. 23, 2015.
Volunteer doctors and paramedics try to revive a baby on Lesbos after a boat carrying more than 200 people sank while crossing from Turkey, Oct. 28, 2015. According to the Greek Coast Guard, three bodies were recovered and 242 people were rescued.
A man hugs his son moments after arriving at Lesbos in a raft from Turkey, Oct. 13, 2015. Dozens of rafts are still making the journey daily as thousands flee conflict in Iraq, Syria, and Afghanistan.
Refugees arrive in Lesbos after crossing from Turkey, Oct. 23, 2015. Many Syrian families with small children are currently forced to walk a distance longer than the Athens Marathon from the beaches where they land to the points of registration near the port capital of Mytilene.
A mother and child rejoice on Lesbos after arriving minutes earlier on a raft from Turkey, Oct. 17, 2015.
People arrive in boats on the shores of Lesbos, Nov. 6, 2015.
A Syrian woman hugs her child as they arrive in Lesbos after crossing from Turkey, Oct. 18, 2015. The Greek Coast Guard said that day that five more people, including a baby and two boys, had died trying to make the crossing from Turkey.
A Syrian family arrive in Lesbos after crossing from Turkey, Nov. 14, 2015.
A local resident cries as she holds the body of a dead baby in Petra village, Lesbos, Oct. 30, 2015.
A man reacts as he arrives in Lesbos after crossing from Turkey, Sept. 27, 2015.
A paramilitary police officer carries the lifeless body of Aylan Kurdi, 3, after a number of refugees died or were reported missing after boats carrying them to the Greek island of Kos capsized near the Turkish resort of Bodrum, Sept. 2, 2015. Aylan's family embarked on the perilous boat journey only after their bid to move to Canada was rejected. The tides also washed up the bodies of Aylan's mother, Rehan, and his 5-year-old brother, Galip. Only Aylan's father, Abdullah, survived the tragedy.
A Syrian woman after arriving in Lesbos after crossing from Turkey, Sept. 27, 2015.
A Dutch volunteer tries to comfort a refugee moments after she arrived by raft to Lesbos, Oct. 23, 2015. Over half a million refugees had arrived by sea in Greece already and the rate of arrivals was rising in a rush to beat the onset of freezing winter, the U.N. said.
Syrian refugees are covered with life blankets upon arrival in Lesbos from Turkey, Sept. 28, 2015.
A Syrian woman collapses on the shore of Lesbos after crossing from Turkey, Sept. 28, 2015.
A man throws his child in the air in celebration after they arrive safely in Lesbos from Turkey, Sept. 28, 2015.
A long-exposure photo shows thousands of lifejackets left by refugees, piled up at a garbage dump site in Lesbos, Nov. 9, 2015.
A young boy sleeps in Bapska, Symia, as he waits to cross the Serbian-Croatian border, Sept. 9, 2015.
A Syrian refugee kisses his daughter as he walks through a rainstorm towards Greece's border with Macedonia, Sept. 10, 2015.
Refugees arrive on the shores of Lesbos after crossing from Turkey on a inflatable boat, Sept. 29, 2015.
Refugees on Lesbos after crossing the Aegean Sea from Turkey on a inflatable dinghy, Sept. 30, 2015.
A baby cries in Lesbos after crossing from Turkey, Sept. 30, 2015.
Around 150 refugees, most of them Syrians, struggle to leave a half-sunken catamaran as it arrives in Lesbos after crossing from Turkey, Oct. 30, 2015.
A refugee carrying a child falls after tripping on TV camerawoman Petra Laszlo (right) while trying to escape from a collection point in Roszke village, Hungary, Sept. 8, 2015. Laszlo was subsequently fired by her employer after videos of her kicking and tripping up refugees fleeing from police spread across the media and over the internet.
A woman arrives in Lesbos after crossing from Turkey, Sept. 30, 2015.
A man comforts his young brother in Lesbos after crossing from Turkey, Oct. 1, 2015.
A young girl arrives in Lesbos after crossing from Turkey, Oct. 1, 2015.
A Danish police officer plays with a refugee girl at the E45 freeway north of Padborg, Sept. 9, 2015.
Syrians sleep on the floor of a train carriage as they travel from Macedonia to the Serbian border, Aug. 30, 2015.
Hundreds of refugees break out from a police holding area and through lines of riot police in Roszke, Hungary, before crossing the M5 motorway, Sept. 9, 2015.
A woman and her children walk after their arrival in the village of Tabanovce, Macedonia, just before the Serbian border, Aug. 30, 2015.
A refugee child sleeps in a rain cover at the border crossing with Slovenia in Trnovec, Croatia, Oct. 19, 2015.
Refugees try to hide from the police in a cornfield near the border between Serbia and Hungary, Sept. 12, 2015.
Danish Muslim World Aid volunteer Sadia Durrani comforts a young Syrian refugee who arrived on the shore on Lesbos, Sept. 12, 2015. The engine of this boat died halfway across the six-mile channel, forcing the refugees into the water, where they pushed and pulled the boat to shore.
Refugees try desperately to board a train heading for Zagreb from Tovarnik station, Croatia, Sept. 20, 2015.
Refugees, mostly Syrians, wait to depart for mainland Greece, Lesbos, Sept. 15, 2015.
Refugees sleep in Horgos, Serbia, at the border after it was closed by Hungarian authorities, Sept. 15, 2015.
Kurdish Syrian Sahin Serko cries next to his 7-year-old daughter, Ariana, minutes after crossing the border into Macedonia with another 45 Syrians, near the Greek village of Idomeni, May 14, 2015.
Syrians cross under a fence into Hungary at the border with Serbia, near Roszke, Aug. 27, 2015.
A Syrian woman feeds her baby inside a car near the highway on her way to the border between Turkey and Greece, Sept. 16, 2015.
Taim Faddiwa, 2, and Bashr Faddiwa, 4, Syrian refugees from Aleppo, sleep alongside their family in Budapest's Keleti railway station after Hungary attempted to send other refugees to a rural processing camp rather than to Germany by train, Sept. 4, 2015.
Young Syrian refugees after disembarking from an overcrowded dinghy at a beach in Lesbos, after crossing from the Turkish coast, Sept. 26, 2015.
Syrians march along the highway towards the Turkish-Greek border at Edirne, Sept. 18, 2015.
A Syrian holds his baby as they arrive in Lesbos in the early hours of the morning, June 18, 2015.
A young man rests on the beach in Bodrum, southwest Turkey, after failing to board a boat to the Greek island of Kos, Aug. 16, 2015.
Two Syrian students dry their documents at a beach in Lesbos, Oct. 19, 2015.
Dima, 5, from Syria, plays with a skipping rope at a refugee accommodation facility in Munich, Germany, Sept. 7, 2015.
A dinghy of Syrian refugees drifts in the Aegean sea between Turkey and Greece after its motor broke down off Kos, Aug. 11, 2015.