France will produce proof "in a few days" that the regime of Bashar al-Assad launched a chemical strike on a Syrian village that killed 87 people earlier this month, Foreign Minister Jean-Marc Ayrault said Wednesday.

"We have elements that will allow us to show that the regime knowingly used chemical weapons," Ayrault said of the suspected chemical attack in Khan Sheikhun on April 4.

"In a few days I will be able to bring you the proof."