Harrelson also starred in Stone's Natural Born Killers

Harrelson will star alongside Bruce Willis in the film based on the infamous My Lai massacre, according to trade paper the Hollywood Reporter.

He will play a colonel in charge of the taskforce who committed the 1968 massacre, when US soldiers killed over 500 men, women and children.

Harrelson previously worked with Stone on the 1994 film Natural Born Killers.

Pinkville will be Stone's fourth film set in Vietnam. His others include the 1987 Oscar-winner Platoon.

Stone's films have often courted controversy

Filming is likely to start next year with a budget of about $40m (�19.9m).

Hundreds of Vietnamese civilians were killed in cold blood at the hands of US troops during the massacre.

The soldiers had been on a "search and destroy" mission to root out communist fighters.

Yet there had been no firefight with the enemy - not a single shot was fired at the soldiers of Charlie Company, a unit of the American Division's 11th Infantry Brigade.

The 48th Viet Cong Battalion - the intended target of the mission - was nowhere to be seen.

It proved to be a watershed in the history of modern American combat, and a turning point in the public perception of the Vietnam War.