WASHINGTON (AFP) - The Pentagon doesn't like Pikachu.

In the latest bizarre news surrounding the global phenomenon that is Pokemon Go, US Defence Department officials on Friday (Aug 12) said employees should not download the game onto their government-issued smartphones.

"You can imagine a number of reasons (why) that wouldn't necessarily be a prudent thing to do," Pentagon deputy press secretary Gordon Trowbridge told reporters.

"Aside from any security concerns, I think taxpayers would appreciate government phones being used for government business."

Pokemon Go is an augmented reality app through which users hunt fictional digitised animal characters like the furry yellow Pikachu, which have been scattered around the world, often in unlikely locations.

The game has become a global craze, with crowds of players dashing to locations to try to snag characters.

Several military installations have warned troops about the possible perils of playing Pokemon Go on bases, including near runways.

Trowbridge jokingly said he could not definitively confirm reports that a Pokemon "gym" - a virtual battle arena - has been placed in the courtyard in the middle of the vast Pentagon building.

"Last I heard, there was still a gym in centre courtyard. I'm not a player myself so I will defer to others," Trowbridge said.

"I can confirm it," quipped Pentagon spokesman Captain Jeff Davis.