The training break was called to allow for more extensive background checks on Afghan police and military recruits, past and present, NATO spokesman Col. Thomas Collins told CNN.
Insurgents have increasingly been infiltrating the ranks of recruits and gunning down their trainers, the report said. In the past month alone, 15 U.S. soldiers were killed by Afghan recruits, The New York Times said.
Afghan Interior Ministry spokesman Sediq Seddiqi said the government agreed with the NATO decision and would work with the coalition to help identify insurgents.
Collins said a system was being set up for Afghan police and soldiers to anonymously report suspicions about other recruits. He said all past trainees will be investigated again more thoroughly, as will future recruits.
He said Afghanistan had agreed to ban the sale of police and military uniforms that allow insurgents access to legitimate forces.