UNITED NATIONS, Rabi'I 07, 1436, Dec. 29, 2014, SPA -- The United Nations said Monday that it has begun delivering food aid to South Sudan via the Nile River from Sudan for the first time since it became independent in 2011. The corridorwill reduce reliance on expensive airplane and helicopter deliveries, which cost six to seven times as much as river and road transport, the World Food Program (WFP) said. "The threat of a hunger catastrophe remains very real in early 2015 as the dry season takes hold," WFP acting country director Stephen Kearney said. "This will make an enormous difference in our efforts to bring food assistance to people in critical need." The Sudan-South Sudan border has been heavily militarized since Juba declared independence from Khartoum three years ago, cutting off almost all cross-border commercial and humanitarian traffic along the Nile. WFP said that the route was opened only after extensive negotiations between the two countries. According to WFP, the agency has completed thousands of flights over the past year carrying food and nutrition supplies to roughly 2.5 million people isolated by conflict and bad roads. In the cross-border operation, the U.N. agency is using trucks and river barges to deliver an initial total of 4,650 tons of food for South Sudanese affected by conflict as well as for refugees living in camps in Maban County of Upper Nile state. WFP said that it hopes to use the re-opened corridor to transport an additional 21,000 tons of food into South Sudan contributed by the United States, which was recently unloaded in Port Sudan in the Republic of Sudan. --SPA 22:34 LOCAL TIME 19:34 GMT www.spa.gov.sa/w