Secretary of State John Kerry was sent out in front of reporters this afternoon with a prepared statement that confirmed the U.S. is preparing a response to “large-scale, indiscriminate” chemical weapons use by the Bashar al-Assad regime in Syria.

“What we saw in Syria last week should shock the conscience of the world,” Kerry said, calling it a “moral obscenity” and adding a plug for President Obama’s past efforts “to stop the proliferation of these weapons.”

Kerry said he spent the night speaking with foreign ministers, at Obama’s direction, then went back and watched many of the videos shot on the ground in Syria showing dead children, families killed in their sleep, bodies “contorting in spasms.”

“Anyone who could claim that an attack of this scale could be fabricated needs to check their own moral compass,” he stressed.

Kerry discussed the chemical attack with Syrian Foreign Minister Walid Muallem and demanded “unrestricted and immediate access” for UN investigators to the areas struck. “Instead it attacked the area further,” he said of the regime’s shelling of the affected region after the chemical weapons attack. “That is not the behavior of a government that has nothing to hide.”

He said the regime’s decision to allow inspectors in today, after five days in which they tried to wipe away evidence, “is too late too late to be credible.”

Obama will be making an “informed decision how to respond to this indiscriminate use” after conversations with other nations and “actively consulting with members of Congress,” Kerry said.

“Nothing today is more serious and nothing is receiving more serious scrutiny,” he added.