Secretary of State John Kerry on Monday called Syria’s use of chemical weapons “undeniable” and indicated that President Barack Obama is plotting action in the coming days.

Setting the stage for eventual military intervention, Kerry said in a statement from the State Department that what is happening on the ground in Syria “is real and it is compelling” and requires a response from the international community. Attacks on civilians by Bashar al-Assad’s regime are, he said, “a moral obscenity” that “should shock the conscience of the world.”

“Make no mistake: President Obama believes there must be accountability for those who would use the world’s most heinous weapons against the world’s most vulnerable people. Nothing today is more serious, and nothing is receiving more serious scrutiny,” Kerry later added.