Of all the foreign countries affected by the Syrian civil war, none has been impacted more seriously than Lebanon, where the Syrian refugee population is approaching 1 million – nearly a third of the Lebanese population.

In Washington on Tuesday, US, UN and Lebanese officials appealed for more support from regional as well as international donors and urged the US Congress not to let budget battles reduce American assistance of $254 million, currently the largest single contribution to Syrian refugee relief in Lebanon.

Lebanese Ambassador to the US Antoine Chedid, speaking at the Woodrow Wilson Center for International Scholars, said the refugee issue was “an existential problem for Lebanon” and urged his country’s “cry of pain” to be heard. He said the Syrian influx into Lebanon was equivalent to 100 million refugees suddenly entering the United States and that the World Bank had estimated the cost to the Lebanese economy over the past two years at $7.5 billion. Without more external help, Chedid implied, Lebanon would have to close its borders to Syrians fleeing the carnage in their homeland.

Anne Richard, assistant secretary of state for population, refugees, and migration, said a third of Syria’s population is now internally displaced or are refugees, who number 2.2 million. More than half of Syrian children no longer attend school, creating a potential “lost generation” that will undermine Syria for years to come even if the war ends soon, she said. Lebanon is hosting more than a third of the refugees, with the remainder in Jordan, Turkey, Iraq and Egypt.