France to provide proof the Syrian government used chemical weapons

French intelligence services will provide proof in the coming days that Syrian President Bashar al-Assad's forces used chemical weapons in an attack on April 4, French Foreign Minister Jean-Marc Ayrault said on Wednesday.

"There is an investigation underway (by) the French intelligence services and military intelligence ... it's a question of days and we will provide proof that the regime carried out these strikes," Ayrault told LCP television.

"We have elements that will enable us to show that the regime knowingly used chemical weapons," he said.