The anti-hunger agency of the United Nations said Friday that it had averted an imminent suspension of food aid to 440,000 Syrian refugees in Jordan after the United States provided a $65 million infusion. In a statement, the agency, the World Food Program, said the American money would enable it to maintain, albeit at a reduced level, food voucher assistance to the refugees, who all live outside camps in Jordan. “This timely contribution has helped us avoid major cuts, but unless other donors step up to the plate, it will be only a matter of months before we face the same situation again,” Muhannad Hadi, the agency’s regional director, said in a statement. The agency, which assists 80 million people in 80 countries, has been vexed by recurring financial travails as humanitarian crises have expanded in the Middle East and Africa.