The military command overseeing $15 billion in U.S. programs to develop Afghanistan''s security forces cannot be sure the money is being managed effectively, a top government watchdog warned Tuesday.

In its first audit report since being formed a year ago, the office of the Special Inspector General for Afghanistan Reconstruction says the Combined Security Transition Command "lacks effective contract oversight capabilities."

It is the command''s responsibility to ensure U.S. tax dollars are spent properly, the audit says. That means command staff must visit locations where contractors are working to verify that contractors are following the terms of their deals with the government.

"This is not happening," the audit said.

Arnold Fields, the special inspector general, said during a telephone interview with reporters there is no substitute for firsthand inspections.

"Those folks need to be on site for an extended period of time," said Fields, a retired Marine Corps general.

He acknowledged that tough conditions in Afghanistan can make long-term visits difficult. But the huge sums of money being spent require that level of oversight, he said.

Fields'' office examined one training contract worth $404 million and found the official responsible for monitoring contractor performance was located at an Army office in Maryland — nine time zones away.