Afghan officials can't account for $3.3 billion in U.S. military aid to their country's military and security forces, according to the Pentagon's inspector general.

There is also no assurance that things will improve after the U.S. delivers $18 billion more such aid already approved by Congress, because Afghan officials aren't using basic accounting and transparency tools, the IG said.

The IG said, for example, that Afghan officials "could not provide a current cash balance for direct contributions or account for currency gains of at least $110.4 million" in funds intended for security forces.

Another $26.9 million was deducted from payments that were made to security forces but Afghan officials couldn't say why or what happened to the funds.

An additional $40 million in U.S. aid intended to pay Afghan military and security forces was simply described by the IG as having been spent "improperly."

The problem is not just with the Afghans, however, because the IG said the American "Combined Security Transition Command–Afghanistan had not held GIRoA accountable for not implementing controls and improper handling" of U.S. aid funds.

American officials have struggled throughout the 13-year history of the U.S. involvement in Afghanistan with that country's government corruption, including millions of dollars being diverted to the Taliban.

The U.S. has provided an estimated $103 billion in aid intended to bolster Afghan military and security forces, and encourage the growth of democratic civil society institutions.

Earlier this year, John Sopko, the Special Inspector General for Afghanistan Reconstruction, told a Middle East Institute that the $103 billion is more than the U.S. has spent on reconstructing any other country, including Germany and Japan after World War II.

Afghanistan's gross domestic product for 2013 was slightly more than $20 billion, while U.S. assistance equalled $15 billion, Sopko said.

Mark Tapscott is executive editor of the Washington Examiner.