The Chilean government says it can't explain a video taken by naval sailors showing a mystery object acting strangely above the country's airspace.

The video from November 2014 taken in broad daylight shows the unidentified object hovering in the sky before dispensing a cloud of gas and flying away.

Naval helicopter pilots tracked the UFO for more than 60 kilometres and made several attempts to communicate with it.

The incident was reported to several nearby radio towers that could not detect the object on sensors.

No aircrafts were authorised to be flying over the airspace at the time.