U.S. Having Trouble Monitoring Spending in Afghanistan

Since the beginning of the United States occupation in Afghanistan in 2001, the U.S. has spent close to $55 billion towards rebuilding the war torn nation. Now, in what is regarded as the first audit report of U.S. spending in Afghanistan,government agencies have not been tracking the actual money spent has not been analyzed and examined. Reports from the pentagon and other government agencies such as the state department and USAID have stated that they cannot accurately report on how much money the country has spent on reconstructing Afghanistan. There are various United States contracting and construction companies that spend money in Afghanistan so it leads to very difficult task to track the entire amount of output. Do you think there is an efficient way to monitor and measure United States economic output towards Afghanistan?