US Secretary of State John Kerry, pushing ahead with his case against the regime of Bashar al-Assad, says the evidence shows Syria used Sarin Gas on its own citizens last month.

“In the last 24 hours, we have learned through samples that were provided to the United States that have now been tested from first responders in east Damascus and hair samples and blood samples have tested positive for signatures of sarin,” Kerry said during appearances on all the major American Sunday morning news shows.

“Bashar Assad now joins the list of Adolf Hitler and Saddam Hussein [who] have used these weapons in time of war.”

Kerry’s statement comes a day after President Obama seemed to pull back on the rush to lob a bunch of cruise missiles at Syria in retaliation for the 21 August chemical weapons attack in the eastern suburbs of Damascus that killed more than 1,400 people.  Obama delayed any action until after a congressional authorization vote, and it’s unclear whether the deeply divided legislators would back the administration.

Kerry added that he did not feel undermined by the President.