JOHN KERRY: Sarin Gas Was Used In Syria - The White House Expects Congress To Approve A Strike

Secretary of State John Kerry says the U.S. now has evidence of sarin gas use by the regime of Syrian President Bashar al-Assad and does not think "that Congress will vote no" in regards to a limited strike in response.

"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 told NBC's Meet The Press.

He added that even if Congress votes against an attack, the president is still ready to proceeed with the plan.

Sarin is a nerve toxin so deadly that just one drop can kill a grown man. The fatality typically comes from cardiac arrest or suffocation, as overstimulated muscles around the heart and lungs eventually seize and stop working altogether.

"We know that the regime ordered this attack, we know they prepared for it," Kerry told CNN's Face of A Nation. "We know where the rockets came from. We know where they landed. We know the damage that was done afterwards. We've seen the horrific scenes all over the social media, and we have evidence of it in other ways, and we know that the regime tried to cover up afterwards, so the case is really an overwhelming case."