WASHINGTON, DC (By ALEXANDER MARQUART/ABC News) -- The regime of Syrian President Bashar al-Assad has used chemical weapons in the two year civil war ravaging Syria, the White House and Pentagon chief announced today.
The accusation could have serious implications for U.S. policies toward Syria.
"The U.S. intelligence community assesses with some degree of varying confidence that the Syrian regime has used chemical weapons on a small scale in Syria, specifically the chemical agent sarin," Defense Secretary Chuck Hagel told reporters in Abu Dhabi, one of several stops during a trip to the Middle East.
"In talking to our intelligence people over the last couple hours, they have a reasonable amount of confidence that some amount of chemical weapons was used," Hagel said.
Moments later, the White House released letters sent to members of Congress repeating Hagel's statement, adding that "this assessment is based in part on physiological examples. Our standard of evidence must build on these intelligence assessments as we seek to establish credible and corroborated facts. For example, the chain of custody is not clear, so we cannot confirm how the exposure occurred and under what conditions."
And on Capitol Hill, Secretary of State John Kerry told reporters that there were two instances of chemical weapons use the U.S. is looking at.
The carefully worded American accusation follows similar allegations by France, the United Kingdom and Israel. On Tuesday, the head of research for Israel's military intelligence told a security conference that "to the best of our professional understanding, the regime has caused death using chemical weapons against [rebel forces] over the last few months."
Speaking specifically about an attack on March 19 near the city of Aleppo in which 26 people died, including regime soldiers, the Israeli official, Brigadier General Itai Brun, said that the chemical used was "probably sarin."
The Obama administration has said repeatedly that the Assad regime's use of chemical weapons would be a "game changer" and would cross a "red line."
Hagel argued today that is it unclear whether red line has been crossed and said more evidence was needed.
"We need all the facts. We need all the information. What I've just given you is what our intelligence community has said they know," he said. "They are still assessing and they are still looking at what happened, who was responsible, and the other specifics that we'll need."
Hagel would not elaborate on evidence studied by the intelligence community and when pressed on what he meant by the community's varying degrees of confidence, he responded: "It means that we still have some uncertainties about what was used, what kind of chemicals were used, where it was used, who used it."
"Given the stakes involved, and what we have learned from our own recent experience, intelligence assessments alone are not sufficient," wrote the White House's liaison to Congress Miguel Rodriguez. "Only credible and corroborated facts that provide us with some degree of certainty will guide our decision-making."