Military scientists at the Pentagon are developing 'talking' lasers which can beam warnings straight into the enemy's head from hundreds of miles away.

Weapons researchers at the Department of Defense say the hi-tech weapon will be able to send brief messages – in the form of audible speech – across combat zones.

The aircraft, ship and truck-mounted devices are being developed as part of a military initiative called the Joint Non-Lethal Weapons Directorate.

The scientists plan to use a phenomenon of physics called the Laser-Induced Plasma formation to make the laser a reality.

First, they fire a powerful laser that creates a ball of plasma. Then, a second laser works to oscillate the plasma creating sound waves.

These intense laser bursts can then perfectly mimic human language, chief scientist Dave Law told the  Military Times.

He added that the technology could be ready for battle in just five years.

A video shared to publicise the Pentagon project shows the weapon saying 'Stop or we'll be forced to fire upon you.'

Scientists say these laser-grams will soon be able to beam hundreds of miles away.