By Carlo Muñoz - 02/11/13 10:04 PM EST
"On the basis of projections of U.S. and other donor support for ANSF for fiscal years 2012 through 2017, we estimate that there will be a gap each year from 2015 through 2017 between ANSF costs and donor pledges if additional contributions are not made," according to the report.
During NATO's annual summit in Chicago last year, Washington and other alliance members agreed to begin making payments of $500 annually to support the ANSF, beginning in 2015 -- a year after the final withdrawal of American combat troops from Afghanistan.
That amount, according to the GAO, would come out to roughly 14 percent of Afghanistan's total domestic revenues for defense and non-defense spending.
Prior to the Chicago summit, the U.S. and its allies had funnelled over $30 billion into Afghan security forces beginning in 2006, with the majority of those dollars coming from American accounts.
"However, even if the Afghan government committed 100 percent of its projected domestic revenues to funding ANSF, this amount would cover only about 75 percent of the cost of supporting security forces in fiscal year 2015," according to the GAO's analysis.
That kind of focus on security spending would force Kabul to abandon or dramatically reduce other non-security programs, such as education and public health, the report states.
Compounding the problem, according to the GAO, is the Pentagon has yet to provide lawmakers any long-term strategy for how it will continue to finance and support the ANSF after 2014.
Pentagon officials claim that such a strategy cannot be drafted with any certainty, due to the fluid security situation caused by the U.S. withdrawal and the growing combat capabilities of the ANSF.
DOD officials, however, do intermittently brief congressional lawmakers on the progress of the ANSF and the changing demands of that fighting force, according to the report.
"This mechanism, however, does not allow for independent assessment of DOD’s estimates to assist Congress as it considers future budget decisions," according to the GAO.
Government auditors do not provide recommendations for how much U.S. and allied investment into the ANSF should be increased by, but ensuring local government forces can take over the security mission in Afghanistan after American forces leave is a key to the administration's 2014 withdrawal plan.
Washington and Kabul are still hammering out the details of what the U.S. postwar involvement will look like in Afghanistan. In January, President Obama announced the United States would be accelerating its handover of security operations to the Afghans.
That handover will now take place this spring, instead of sometime in 2014 to coincide with the American pullout.
At the time, Obama said the ANSF were in a secure enough position in the country to shoulder those operations against the Taliban and other extreme Islamic groups fighting in the country.