The chairman of the House Intelligence Committee on Sunday warned there was “mounting evidence” Syrian President Bashir al-Assad has used chemical weapons and said the red line calling for a U.S. response “has been crossed.”

“When you look at the whole body of information over the last two years, there is mounting evidence that the Assad regime has used at least a small quantity of chemical weapons throughout the course of this conflict," said Chairman Mike Rogers (R-Mich.) on CBS’s “Face the Nation.”