Defense Secretary Hagel Says Syria Has Used Chemical Weapons

March 25, 2013 -- 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.

But officials at the White House said they want more time to examine the evidence and confirm beyond doubt the Assad regime crossed the all-important "red line" by using chemical weapons.

The accusation could have serious implications for U.S. policies toward Syria and lawmakers from both parties argued Thursday that addition action must be taken against Syria.

The American assessment that chemical weapons had been used in Syria first came from Defense Secretary Chuck Hagel.

"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." 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.

Related: Read More About Syria

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."

Related: Obama Said Syrian Use of Chemical Weapons Would Be "Red Line"

Syria doesn't publicly admit to having chemical weapons, though its arsenal is believed to be one of the biggest in the world. But in a press conference last July, a spokesman for the Foreign Ministry acknowledged their existence and said they would only be used against foreign threats.

"Any stock of WMD or unconventional weapons that the Syrian army possesses will never, never be used against the Syrian people or civilians during this crisis, under any circumstances," said Jihad Makdissi, who has since defected from the regime. "These weapons are made to be used strictly and only in the event of external aggression against the Syrian Arab Republic."

Senator John McCain, R-Ariz., told reporters an hour-long briefing from Kerry that its "pretty obvious" the red line has been crossed in Syria.

"The president of the United States said this would be a red line if they use chemical weapons," said McCain. The president of the United States has now told us that they used Chemical weapons. Those stocks of chemical weapons, some of which are in disputed areas, must be secured and we must give the opposition the capability to drive out Bashar al-Assad once and for all. And our relations with Russia should be directly related to their assistance to Bashar al-Assad which is significant."

McCain called on the Obama administration to step up to the plate.

Senator Lindsey Graham, R-S.C., said the US needs to move "quickly" to secure the chemical weapons from falling into the wrong hands and contain the fighting to protect the King of Jordan, a U.S. ally. He said the U.S. shoudl seek to control the "inevitable second war" in Syria.

"There are up to six thousand al Qaeda type fighters now in Syria, the country is fragmenting along with sectarian violence and chaos is reigning," Graham warned. "The day that Assad falls there will be as surely as I'm standing here a conflict between the majority of Syrians who want to move forward and live in peace and small element of radical jihadists. And that conflict needs to be planned for and brought to an end. So the sooner Assad leaves the better for the world. "

A Democrat, Sen. Dianne Feinstein of California, said action must be taken against Syria. And she urged the U.N. Security Council, including Syria's ally Russia, to take the lead.

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."

ABC's Luis Martinez at the Pentagon, Mary Bruce at the White House and Sunlen Miller on Capitol Hill contributed to this report.