The UN refugee agency and Syria's overburdened neighbours Lebanon, Turkey, Jordan and Iraq on Wednesday urged the international community to put differences aside and find a common solution to end the "cycle of horror".
While Washington and Moscow insist they both want a political solution to the conflict in the shape of negotiations, Syria's ally Russia has repeatedly frustrated the US by blocking UN Security Council action against the regime of President Bashar al-Assad.
"We strongly appeal to the international community to overcome existing differences and come together to stop the fighting," said Antonio Guterres, the UN High Commissioner for Refugees, as he read a joint statement after talks with ministers from the four countries.
"A political solution to end this cycle of horror is urgently needed. There is no humanitarian solution to the Syrian crisis. Rather there needs to be a political solution that ends the humanitarian crisis," he said.
Guterres was flanked by Lebanon's Minister of Social Affairs Wael Abu Faour, plus Jordan's Foreign Minister Nasser Judeh and his Turkish and Iraqi counterparts Ahmet Davutoglu and Hoshyar Zebari.
The four countries have received the overwhelming majority of the two million Syrians who have fled their homeland since the war started in March 2011, and are being stretched to the limit as they cope with the influx.
On average, some 5,000 Syrians continue to flee their country every day, according to UN data.
Counting refugees and the estimated 4.2 million people the UN says have been displaced within Syria, nearly a third of the country's pre-war population of 20.8 million have now been uprooted. The conflict has claimed over 100,000 lives.
"What Turkey, Lebanon, Jordan and Iraq are doing is an enormous service on behalf of the international community as a whole," Guterres said, adding that the nations were "paying an extremely heavy price" for their generosity.
"The impact of such a large number of refugees on their economies, their societies, the impact of a conflict next door on their national security, is something that needs to be fully recognised by the international community," he said.
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As a result of the war, Lebanon's population has risen by more than a fifth and Jordan's by over 10 percent.
There are 720,000 registered refugees in Lebanon, 520,000 in Jordan, 464,000 in Turkey and 200,000 in Iraq, according to UNHCR data, though the real numbers could be far higher.
With most of the refugees living within local communities rather than camps, everything from food and water supplies to education and health services are under massive strain, while the labour market has gone askew and prices have climbed fast.
"This is the humanitarian spillover of the political and military violence taking place in Syria," said Jordanian minister Judeh.
"The magnitude of this humanitarian crisis has proven to be beyond the ability of any country to deal with," he added, while Iraq's Zebari said numbers were certain to snowball in the absence of "durable, political solutions".
Lebanon's Faour said his country was committed to host and protect Syrians, despite the heavy burden, a message echoed by his counterparts.
"The response of the international community to this crisis is frustrating. It's frustrating on the humanitarian level. It's frustrating on the political level," Faour said.
The number of people flooding out of Syria has risen after the regime's alleged use of chemical weapons against civilians and fears of Western military action.
"We are at another threshold," said Davutoglu of Turkey.
"If this violence against civilians continues like before and there is no international reaction to it, we are scared that all neighbouring countries will be facing much bigger numbers of refugees," he warned.
"These are the numbers, but these are human beings. We are all human beings. This is the cry of humanity. Enough is enough!"