A “critical gap” in funding for Syrian refugees and host communities this year could lead to cuts in vital services, threatening social stability in host countries and refugees’ futures, UN and aid agencies warned on Thursday. Humanitarian organizations had asked international donors for $5.6 billion this year to support 5.5 million Syrian refugees living in Jordan, Lebanon, Turkey, Iraq and Egypt, and 4 million nationals from those host countries. Only 18 to 22 percent of required funds have been given so far this year, the heads of several UN agencies said at a conference in Amman to ask for more aid. The UN had already expressed concern that 2018 aid pledges fell short of targets after a Brussels donor conference in April, Reuters said.