But Mr. Harper said the United Nations and the nonprofit groups helping it run the camp were doing the best with what they had, noting that the agency had appealed for $245 million to absorb Syrians regionwide in 2012 and received $157 million. Jordan, already consumed with an intense financial crisis and a growing protest movement, is scrambling to keep up with the influx. Its task is particularly complex given the delicate balance in its population of six million, which is dominated by Palestinian refugees and their descendants and includes hundreds of thousands who fled the war in Iraq.

Zaatari is only the most visible challenge. Nearly five times as many refugees are living in Jordanian cities and villages, taxing the government’s resources, and competing for scarce jobs.

Anmar Hmoud, who is handling the Syria file for the prime minister, said that refugees could leave Zaatari and Jordan’s handful of smaller camps if a relative or friend could guarantee financial support, but that the government was “exhausting its own resources.” He estimated the cost of military, health, education and other services at $670 million for 2012 and 2013.

“We are a neighbor, and we do our duty, but there is a limit to helping people unless we are helped by others,” he said. “It’s not the Jordanian problem, it is the international community’s problem.”

Some relief is coming. Mr. Hmoud said a new camp just south of here near Zarqa, financed by the United Arab Emirates, would open in two weeks, allowing 6,000 of Zaatari’s most vulnerable residents to move into prefabricated homes, and eventually growing to accommodate 30,000. Saudi Arabia, which over the past month has provided Zaatari with 2,500 prefabs costing $8 million, announced Friday that it would give $10 million more to the Jordanian effort. Mr. Harper said he had met with envoys from Qatar and the Emirates.

“It’s terrible to say, but sometimes it takes a miserable situation like we’re having now to get people to say, ‘Yes, we can do something,’ ” Mr. Harper said.