Amnesty International is urging world leaders to overhaul refugee policies and create a comprehensive global strategy to deal with the crisis.
The human rights watchdog issued a report on June 15 suggesting that world leaders have abandoned millions of refugees to "an unbearable existence" and left thousands more to die by failing to provide basic human protections.
The report estimates that 4 million people have fled Syria, with most living in poor conditions in Turkey, Lebanon, Jordan, Iraq, and Egypt. Amnesty says these countries are struggling to cope with the influx.
Salil Shetty, the group's secretary-general, described the refugee crisis as one of the defining challenges of the 21st century, "but the response of the international community has been a shameful failure."
Shetty is urging states to share responsibility internationally.
Based on reporting by AP and www.amnesty.org