Don't reject refugees from Syrian civil war, U.N. tells world BEIRUT -- The United Nations has called on nations not to turn back Syrian civil war refugees, whose swelling ranks now constitute the world's fastest-growing refugee flow in almost 20 years. "I reiterate my call to all states in the region and further afield to keep their borders open and receive all Syrians who seek protection," U.N. High Commissioner for Refugees Antonio Guterres told the Security Council in New York on Tuesday via video link from Geneva. In recent weeks, several of Syria's neighbors, along with Egypt, have made it more difficult for Syrians to enter their countries. The new restrictions mirror grave concerns among some nations about the mounting economic and social costs of hosting an ever-escalating refugee population. Turkey and Jordan, which together are sheltering more than 1 million Syrians, are now allowing only gradual entries because of what the U.N. called "security concerns." Another Syrian neighbor, Iraq, "has shut its borders, slowing arrivals to a trickle," Guterres said. Away from Syria's borders, some passenger flights from Syria to Egypt were turned back last week amid Cairo's imposition of a visa requirement and security clearance for arriving Syrians. More than 90,000 Syrian refugees have fled to Egypt. Only Lebanon, home to more than 600,000 Syrian refugees, remains "completely open" to Syrians, Guterres said, but Lebanon has paid a considerable price. The refugee wave has contributed to a tense social and political atmosphere in Lebanon, where elections scheduled for June were put off and a caretaker government now rules. Lebanon's "political system is paralyzed and will likely remain so until the Syrian crisis is over," said the U.N. refugee chief. The U.N. has registered about 1.8 million Syrian refugees, mostly in nation's bordering Syria, but officials say the actual number tops 2 million, since many refugees have not signed up with the U.N. Since the beginning of 2013, the U.N. said, an average of 6,000 people a day have been fleeing Syria - the fastest growing refugee flow since the mass killings in Rwanda in 1994 spurred an exodus from that African nation. Inside Syria, millions more have been displaced because of the fighting. By some estimates, the war has forced as many as 1 in 4 Syrians from their homes. The more than 2-year-old Syrian conflict has also left more than 90,000 dead, according to the U.N. All efforts to craft a negotiated settlement have failed. "While Syria continues to drain itself of its people, the prospects for a political solution and an end to the fighting remain poor," Guterres said. The warning signs of destabilization in some neighboring countries are troubling. Egypt appoints new Cabinet; Mosi backers clash with police