Due to increased security concerns, the U.S. military has started classifying various basic statistics about its involvement with Afghanistan's security forces.

Information such as the number of uniformed Afghan soldiers and police officers is now considered classified, after the top U.S. military commander in Afghanistan said it could assist the Taliban in planning attacks against the 10,600 U.S. troops working to train Afghan forces, reported The New York Times.

How much taxpayers pay to teach Afghan soldiers to read and write, and the amount of money spent on weapons and gear for Afghan military and police - all secret.

For six years, the Special Inspector General for Afghanistan Reconstruction (SIGAR) produced quarterly reports tracking the progress of the $65 billion spent by the U.S. to improve Afghanistan's infrastructure, security forces and other development.

Information about Afghani troop numbers, salaries, training equipment and attrition rates was all made publicly available.

The most recent report, released today, includes all of that information in a classified appendix only available to government officials with sufficient security clearance, reported ABC News.

More than 140 questions asked by SIGAR were not answered because they were classified, according to NPR.

"I am deeply concerned with the implications of this sudden classification decision and have raised it with the appropriate officials," said John Sopko, the Special Inspector General for Afghan Reconstruction.

In a letter addressed to Sopko, commander of U.S. forces in Afghanistan, Gen. John Campbell, explained his decision.

Campbell said he couldn't explain why certain information was considered unclassified in the past, but "I can advise that given the risks that continue to exist to our forces and those of Afghanistan, I have directed that sensitive operational information or related materials, that could be used by those who threaten the force, or Afghan forces, be classified at an appropriate level."

"With lives literally on the line," Campbell continued, "I am sure that you can join me in recognizing that we must be careful to avoid providing sensitive information to those that threaten our forces and Afghan forces, particularly information that can be used by such opposing forces to sharpen their attacks."