WASHINGTON - The US military is seeking to shore up a weak supply chain through Pakistan and Central Asia as it prepares to expand its Afghan presence, officials say. The plan is to increase the flow of supplies into Afghanistan by at least 50 percent to support an anticipated buildup of tens of thousands of troops, The Washington Post says. Now reported undergoing testing is the first shipment of US military non-lethal cargo such as food, fuel, water and building materials through Russia. About 90 percent of such goods to Afghanistan go through Pakistan and officials say some Afghan roads are so dangerous the military has to fly over them. Some 130 contract drivers have been reported killed trucking US supplies through Pakistan, US Air Force Gen Duncan J McNabb, commander of the US military's Transportation Command, told the Post.