Emmanuel Macron has said any use of chemical weapons would  be a 'red line'. Pics/AFP

French President Emmanuel Macron has said that he would respond to "proof" that the regime of Syrian President Bashar al-Assad had used chemical weapons, "at a time of our choosing." "We have proof that chemical weapons were used last week, at least chlorine, and that they were used by the regime of Bashar al-Assad," Macron said during an interview on France's TF1 television.