Port-au-Prince , Haiti ( CNN ) -- At least one organization attempting to deliver aid to Haiti continued to be plagued Sunday by delays and logistical problems , but aid was getting to those who need it most , officials said . Doctors Without Borders said Sunday that , despite guarantees from the United Nations and the U.S. Defense Department , its cargo plane carrying an inflatable surgical hospital was blocked from landing in Port-au-Prince the day before and was rerouted to Samana , Dominican Republic . Samana is in the eastern portion of the Dominican Republic and across the Caribbean island of Hispaniola , shared by the two nations , from Port-au-Prince . The material was being sent by truck from Samana , said the group , also known in French as Médecins Sans Frontières . However , the re-routing added a 24-hour delay to the hospital 's arrival . A second Doctors Without Borders plane was able to land on Sunday . That plane carried additional medical supplies and hospital equipment , the group said , adding it is still concerned about delays in the delivery of vital supplies . `` If this plane is also rerouted , then the hospital will be further delayed , in a situation where thousands of wounded are still in need of life saving treatment , '' a group statement said . It was unclear Sunday afternoon whether the plane had landed . See photos , details of some of the missing in Haiti . The surgical hospital includes two operating theaters , an intensive-care unit , 100-bed hospitalization capacity , an emergency room and all the necessary equipment needed for sterilizing material . `` MSF teams are currently working around the clock in five different hospitals in Port-au-Prince , but only two operating theaters are fully functional , while a third operating theater has been improvised for minor surgery due to the massive influx of wounded and lack of functional referral structures , '' the organization said . The group said two of its medical teams have performed more than 100 operations since arriving in the country , but frustrations are high over the delays . An emergency communications officer with the group in Haiti said conditions are growing worse for patients and `` we need the inflatable hospital -- if it ever arrives . '' `` Patients who were not critical only three days ago are now in critical phases , '' she wrote in a news release . `` This means that people will die from preventable infections . It 's horrible . '' Planes are asked to divert elsewhere if they do n't have the fuel to stay in a holding pattern , Col. Buck Elton of U. S. Special Operations Command South told reporters Sunday . Only two planes had been diverted Sunday , he said . Asked about the matter on CNN 's `` State of the Union '' Sunday , Lt. Gen. P.K . Keen , deputy commander of U.S. Southern Command , said the Port-au-Prince airport , which is being run by the U.S. military , is operating at maximum capacity 24 hours a day . `` It 's a matter of balance between getting relief supplies on the ground , getting the people on the ground that are necessary to get those relief supplies distributed , and getting the logistical capacity on the ground to continue that , and the vehicles so we can get it out by ground as well as by air , '' he said . Full coverage of the earthquake in Haiti . More aid was on the way . The National Organization for the Advancement of Haitians held an earthquake survival kit drive at the Haitian embassy in Washington , saying it was accepting items including baby formula , diapers , toiletries , vitamins , medicines , batteries and clothing . Hundreds of people turned out , and they brought enough to fill several trucks full . The overflow of supplies was piled along the embassy 's walls and stairwells . U.S. paratroopers using helicopters from an aircraft carrier delivered 130,000 daily-ration packets on Saturday , Keen of U.S. Southern Command said on `` Fox News Sunday . '' Some 70,000 bottles of water were also delivered , he said . One helicopter could not land and was forced to drop supplies , Keen said , but the delivery otherwise encountered no problems and was orderly . Keen called it a good day . Also Saturday , a member of the U.S. Coast Guard helped deliver a Haitian newborn aboard a Coast Guard helicopter . The mother -- one of five Haitians the Coast Guard was transferring from Port-au-Prince to Cap Haitien for medical reasons -- went into labor as the helicopter was refueling aboard the Coast Guard Cutter Tahoma , the Coast Guard said . The mother and child were taken to a hospital in Cap Haitien and were in good condition , according to the Coast Guard . In Washington on Sunday , hundreds of people from different faiths mourned the victims of the quake and donated money during a service at the National Cathedral . Among those in attendance were Susan Rice , the U.S. ambassador to the United Nations , and Raymond Joseph , the Haitian ambassador to the United States . Joseph asked the mourners to continue that support even as the tragedy fades from the headlines . `` I 'm thanking you in the name of the people of Haiti and I 'm asking you that what you 've begun here tonight should n't stop -- it should continue until Haiti gains its place among the nations of the world , as it should . `` Please , stay with us until we totally rebuild , '' Joseph said . The World Food Programme said it reached 40,000 people in and around Port-au-Prince with high-energy biscuits . The organization said its goal is to reach another 60,000 people on Sunday . Convoys and shipments carrying ready-to-eat foods continue to arrive , the group said . The WFP 's convoy was the first food to arrive in Leogane , about 18 kilometers ( 11 miles ) west of Port-au-Prince and close to where the earthquake was centered , it said in a statement . Nearly every building collapsed , and tens of thousands of people are believed to have been killed . Survivors are living in makeshift camps . In addition , the organization was distributing hot meals in some places , such as hospitals and schools , and has begun setting up kitchens at distribution sites , it said . The Red Cross said in a statement Sunday it had built latrines for 1,000 people and supplied medical kits for 2,000 patients to two hospitals . Seven truckloads of medical supplies should arrive in Port-au-Prince Sunday night , it said . Keen told CNN 's `` State of the Union '' on Sunday that the United States intends to continue helping Haiti as long as there is a need . Former Presidents Bill Clinton and George W. Bush kicked off a fundraising drive Saturday -- a donation push called the Clinton Bush Haiti Fund . George W. Bush told CNN 's John King in an interview that aired Sunday , `` One thing I am concerned about is that on these -- during these crises , all kinds of fake charities spring up . ... We will make sure the money is accounted for and there 's transparency , and [ it is ] properly spent . '' CNN 's Karl Penhaul , Arthur Brice , Elise Labott , Laurie Ure , Greg Clary and Dugald McConnell contributed to this report .
Aid beginning to reach those who need it , officials say . One aid group still experiencing delays in getting aid into country . Port-au-Prince airport running at maximum capacity , U.S. general says .