Kerry: Hair, Blood Samples Test Positive for Sarin Poisoning

Secretary of State John Kerry makes a statement about Syria at the State Department in Washington, Friday, Aug. 30, 2013. Kerry said the U.S. knows, based on intelligence, that the Syrian regime carefully prepared for days to launch a chemical weapons attack. (AP Photo/Charles Dharapak)

Secretary of State John Kerry announced Sunday that new evidence showing the use of Sarin gas in the Damascus, Syria, attack perpetrated Aug. 21.

According to an NBC News transcript cited by the Washington Post on Sunday, Kerry said in an interview with “Meet the Press”: “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.”

“So this case is building and this case will build,” he said.

The U.N. began its investigation on August 26 into allegations of chemical weapon use by the Syrian regime. U.N. investigators left Syria on Saturday as U.S. President Barack Obama announced he would be willing to proceed with a military strike on Syria to quash any further chemical weapon use, even without U.N. Security Council approval.

Obama said he would wait for Congress to vote on a military strike when it resumes session September 9.

The U.N. investigators were set to brief U.N. Secretary General Ban Ki Moon Sunday.