"We don't want to give the enemy any unfair advantage", US Army Col. Rob Manning, a Pentagon spokesperson, told reporters on Monday.
The restrictions were issued some six months after the location and movements of USA troops were included in a usage map published by the Strava fitness tracking company.
Troops in deployed locations are immediately prohibited from using the geolocation features in private and government devices unless a military combatant commander authorizes it, the Pentagon memo said, the Examiner reported.
"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 memo states".
Army Col. Rob Manning, a Pentagon spokesman, said it's a move to ensure the enemy can't easily target USA forces.
Data released by Global Positioning System tracking company Strava in November 2017 shows where the users of fitness devices are around the world, including Kandahar Airfield in Afghanistan, as shown in this screenshot.
The policy memo appeared in a Pentagon memorandum issued on Friday.
Military leaders will be able to conduct risk assessments to determine whether troops under their command can use the devices in the area or on the base they are located.
Observers noted that few local residents owned the devices and that the activity seen on the heat map allowed for the mapping of military bases and potentially even top secret sites.
Defense officials anxious that individuals could use the map to identify running routes around remote or classified USA military bases or in warzones, suggesting that soldiers' lives could be at risk.
For now, it's unclear what will happen to any Pentagon personnel caught using location-tracking devices.
That memo called for stricter adherence to long-held practices that require phones be left in storage containers outside secure areas where sensitive matters are discussed.
Strava apparently intended no harm but, you can guess how uneasy this made service members and senior Pentagon officials.
Many popular devices and applications, including smartphones, smart watches, fitness and dating apps use geolocation and some applications could potentially not work with the geolocation features turned off.
Annual Cybersecurity Awareness training will also be updated to assist DoD personnel in "identifying and understanding risks posed by geolocation capabilities embedded in devices and applications".