Austrian Chancellor Werner Faymann and German Vice Chancellor Sigmar Gabriel on Saturday called for United Nations countries to contribute an extra five billion euros ($5.65 billion) in aid for refugees living in camps in Lebanon and Jordan.
"We have to help countries where the misery is so great that people are going on the road," Gabriel said, in reference to the tens of thousands of migrants -- many of them Syrian refugees -- who have headed to Europe in recent months.
"If people have nothing to eat and drink, what can they do but flee? No barrier in the world will stop them," Gabriel told a press conference.
In a thinly veiled reference to Hungary, which has been fencing off its borders in a bid to keep the migrants out, Faymann said: "A country can build a fence and try to pass on the responsibility to provide humanitarian aid to its neighbours," but added that "international solidarity" is needed to solve the crisis.
The United Nations estimates that Jordan is hosting 600,000 Syrian refugees, while the government puts the figure at up to 1.4 million.
Tiny Lebanon, which has a population of only four million, is currently hosting more than 1.1 million Syrians forced from their homes by their country's brutal civil war.
Berlin called last week at a meeting of G7 and Arab countries for more funds for the UN refugee agency.
Europe is facing its biggest migration crisis since World War II as it struggles to cope with a massive influx of migrants fleeing conflict and poverty in the Middle East and elsewhere.
The International Organization for Migration said this week that nearly 474,000 people braved perilous trips across the Mediterranean to reach Europe this year.