Amnesty International launched its report Global Refugee Crisis: A Conspiracy of Neglect at a news conference in Beirut on Monday 15 June.
Secretary general Salil Shetty said: "Given the exceptional crisis situation, it would be reasonable to expect the international community to organise an exceptional response. Sadly, the response of the international community has been dismal and disappointing.
"Eighty-six per cent of those who have been displaced and who are refugees are living in developing countries facing serious hardships when they live in those countries because many of those countries are themselves poor, or middle-income, and cannot afford to host these refugees. Ninety-five per cent of Syrian refugees are hosted in the neighbouring countries, particularly Turkey, Lebanon, Jordan, Iraq."
The US-based NGO urged Syria's neighbours to end severe restrictions imposed on refugees fleeing the war-torn country, saying it has virtually prevented thousands of desperate Syrians from escaping the ongoing violence.
The situation was so desperate that Syria's neighbours had resorted to "deeply troubling measures, including denying desperate people entry to their territory and pushing people back into the conflict," Shetty added.
The human rights organisation said Lebanon, Jordan, Turkey and Iraq, countries which among them host over four million Syrians who have fled since 2011, should exempt refugees from pre-entry visas or residency requirements now being imposed.
The failure of the international community to adequately fund refugees' humanitarian needs or to support their host countries through settlement policies has had a "devastating effect on people fleeing the conflict", Shetty said.
Syrian refugees faced with reduced humanitarian assistance and with no prospect of returning home in the near future are likely to continue to attempt to cross the Mediterranean, the most dangerous sea route for refugees, to reach Europe, Shetty said.
As of 31 May 2015, 1,865 people had died attempting the Mediterranean crossing, compared with 425 during the same period in 2014, the report said.
Syria's neighbours, who are now struggling to cope with what the international rights group termed "the world largest refugee crisis", are in some cases forcibly deporting Syrians and rejecting the entry of stranded refugees on the border, the rights group said.
Since the beginning of 2015 Lebanon, which hosts over 1.2 million refugees, has severely restricted the entry of people fleeing Syria, leading to a steep drop in refugees.
In the first three months of 2015, UNHCR registered 80% fewer refugees in Lebanon than in the same period the year before.
Jordan, which hosts 627,287 refugees, has effectively closed the door to most Syrians seeking refuge, in violation of its international obligations.
"Fundamentally, we are calling for the number of refugees which the UN has asked to be resettled, which is over a million refugees that are in urgent need, and we are calling on the international community to resettle them at the rate of 300,000 a year for the next four years. We are calling for a global refugee fund to be created, we are calling for an international summit, an urgent international summit to be held, and we are calling for this to happen now. The world can't wait any longer," said Shetty.
According to Amnesty International, more than 50 million people in the world have been pushed out of their homes and among those 16 million are officially categorised as refugees.