The group claims Afghan journalists have called the directive a form of intimidation and predicted it would have a deleterious effect on reporting.
On June 20, Paris-based Reporters Without Borders voiced its "dismay" at the Afghan government's perceived efforts to "impose censorship and self-censorship about the security situation and the presence of foreign troops."
In a statement posted on its website, Reporters Without Borders said it is "absolutely outrageous" that the Afghan authorities would tell the privately owned media what to say and write.
AFP reported that the 24-point directive sets out no penalties for failing to comply.
President Hamid Karzai's office defended the move, reportedly telling AFP that the government simply "requested the local media organizations in Afghanistan to refrain from glorifying terrorism, or giving terrorists a platform."