Troops in “operational areas” such as warzones or overseas US bases can now be required to disable their electronic devices’ geolocation services.
GPS tracking, which is present on most phones and smartwatches, enables fitness tracking and even dating apps.
The move comes after a fitness app revealed US troop movements in Syria.
The Pentagon had launched a review of GPS trackers and apps earlier this year after fitness tracker Strava released a global map of users.
The Global Heat Map showed what appeared to be Western soldiers either running or cycling in Helmand, Afghanistan and Tanf, Syria, on frontline bases.
“The rapidly evolving market of devices, applications, and services with geolocation capabilities… presents significant risk to Department of Defense (DoD) personnel both on and off duty, and to our military operations globally,” the order says.
“These geolocation capabilities can expose personal information, locations, routines, and numbers of DoD personnel, and potentially create unintended security consequences and increased risk to the joint force and mission.”
The order stops short of banning smart devices and fitness tracking electronics themselves, but allows commanders to determine when they can be used.