The UN refugee agency UNHCR said on Thursday that the number of Syrian refugees in other countries has exceeded 4 million, adding that the total is on course to reach 4.27 million by the end of 2015.
"This is the biggest refugee population from a single conflict in a generation. It is a population that needs the support of the world but is instead living in dire conditions and sinking deeper into poverty," UN High Commissioner for Refugees António Guterres said in a statement.
Countries hosting Syrian refugees include Jordan, Iraq, Egypt, Lebanon and Turkey, with Turkey holding more refugees than any other country. In total around 1.8 million Syrians are living in different areas of Turkey.
The number of Syrians who have asked for asylum in Europe has reached 270,000, with 7.6 million Syrians displaced within Syria.
"Worsening conditions are driving growing numbers towards Europe and further afield, but the overwhelming majority remain in the region," Guterres said. "We cannot afford to let them and the communities hosting them slide further into desperation."
A UNHCR appeal for $5.5 billion to support the Syrian refugees in 2015 has only received 24 percent of its target.
Due to of a lack of cash, the UN World Food Programme has already cut rations for refugees.
About 86 percent of Syrian refugees in Jordan, around 630,000 people, live below the international poverty line of $3.2 per day, the UNHCR statement said. More than half of the 1.173 million Syrians in Lebanon live in substandard shelters.