On his first visit to Washington since being appointed to head the UN refugee effort, Filippo Grandi said the world must do more to end the crisis.
"On March 30, I'm going to chair a meeting in Geneva at which I ask the international community to take 10 percent of all the Syrian refugees," he said.
"Ten percent is a lot of people. It's more than 400,000 people," he told reporters, on the fifth anniversary of Syria's bloody civil war.
More than four million Syrians have fled their war-torn country since the conflict erupted, and more than six million are displaced within its borders.
Neighboring Turkey, Lebanon and Jordan are struggling to cope with the exodus and the onward flow has created a political and humanitarian crisis in Europe.
Canada and Germany have been praised for stepping up to welcome tens of thousands as refugees, but others, including the United States, have been criticized.
Historically the United States has been by far the world's leading host of refugees, and it still is for those fleeing many other conflicts around the world.
But, amid a bitter atmosphere in the run up to November's presidential election, Washington has struggled to offer new homes to desperate Syrians.
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US President Barack Obama ordered that 10,000 be admitted during the 2016 fiscal year, but half-way through the period only 1,115 have been processed.
Grandi was careful not to criticize his hosts in Washington, praising the leading US role in hosting refugees of other nationalities.
But he lamented the tone of the debate in both the US and Europe, where anti-immigration politicians have claimed that terrorists hide among Muslim refugees.
Grandi complained that on a visit to the European parliament he had heard "language we haven't heard since the 30s" from opponents of resettlement.
But he added that the new 400,000 target figure could be met in part by means short of the full resettlement package that the United States offer.
Rather than providing Syrian refugees with new lives and permanent residence, some countries may offer temporary jobs, scholarships or humanitarian visas.
For this, he said, his office would work with private firms and universities in partnership with states, to try to reduce the pressure on Syria's neighbors.
That, he argued, is the least the world can expect -- at least until the tentative Syrian peace process underway in Geneva leads to a negotiated peace.
"We're really observing one of the worst political failures in modern history," Grandi complained.
"The failure of the parties to the conflict. The failure of the regional powers. The failure of the global powers to get them to come to an agreement.
"In the absence of that -- and we have to be hopeful -- it is important to show solidarity in every possible way," he said.