The United Nations and a number of humanitarian groups are calling for $461.2 million in aid for Palestinians, in the wake of a border crossing closure in the Gaza Strip that is reportedly causing serious humanitarian problems. Twelve UN agencies and 15 international and 13 national non-governmental agencies are launching the appeal. The amount is said to be the largest appeal ever for the Occupied Palestinian Territory and is the third largest after appeals for Sudan and the Democratic Republic of the Congo. UN Humanitarian Coordinator Maxwell Gaylard said in a release on Tuesday that the closure of the Karni crossing into Gaza, where most humanitarian supplies cross into the area, “is of mounting concern.” “Closures not only hurt the economic well-being of families and communities in the occupied Palestinian territory, they also erode the basic human dignity of the Palestinian population,” he said. “It is for this reason that we call for continuing support for our efforts in bringing real and meaningful assistance where it is most needed in the West Bank and Gaza,” he added. In a release, he said 57 percent of Palestinian households are living in poverty. In the Gaza Strip, around 79 percent of households are poor. In support of the appeal, the deputy head of the UN agency charged with helping Palestinian refugees warned that Gaza's closure could cause a serious crisis. “The situation in the West Bank and Gaza is dire and getting worse. With the total shut down in Gaza, the vast majority of people there are now dependant on United Nations assistance, which is now in serious jeopardy,” said Filippo Grandi, deputy commissioner general of the UN Relief and Works Agency.