The United States and other donors funded about 90 percent of Afghanistan’s estimated total public expenditures from SY2006 to 2010. In particular, donors funded on average 57 percent of on-budget expenditures and 100 percent of off-budget expenditures. Over this period, the United States provided 62 percent of estimated total public expenditures, while other donors provided 28 percent. The United States funded an estimated 90 percent of Afghanistan’s total security expenditures during this time period. The United States funded an estimated 39 percent of Afghanistan’s total non-security expenditures during SY2006 to 2010.
GAO report here