After Kerry Cites Evidence of Gas Attack

U.S. Ambassador to UN: Assad Used Chemical Weapons Against Civilians

Samantha Power is first U.S. official to directly accuse Syria regime of using chemical weapons on civilians; CBS reports that Obama ordered advisers to compile document justifying Syria strike.

U.S. Ambassador to the United Nations Samantha Power on Tuesday accused Syrian President Bashar Assad of using chemical weapons against Syrian citizens.

U.S. Secretary of State John Kerry said on Monday that the evidence of a massive deadly chemical attack last week was "undeniable" and accused the Syrian government of trying to cover it up, signaling the United States was edging closer to a possible military response.

Power went one step further in a tweet on Tuesday and directly accused Assad of using chemical weapons against civilians.

"Haunting images of entire families dead in their beds. Verdict is clear: Assad has used CWs against civilians in violation of int'l norm," Power tweeted.

U.S. President Barack Obama has ordered his national security team to prepare a declassified report that would detail justifications for a military strike on Syria, CBS News reported Monday.

Obama convened his national security advisers on Saturday to discuss the U.S. response to a chemical weapons attack that reportedly killed hundreds outside Damascus on August 21.

The security experts reviewed evidence that Washington believes leaves "very little doubt" that the Syrian government was behind the attack.

According to CBS, the team agreed that military response is necessary. Obama requested to draw up legal justifications required to launch such a strike without the backing of the United Nations Security Council, with emphasis on Syria's alleged violation of the Geneva Convention and the Chemical Weapons Convention.

The news network cited senior advisers as saying that the report would be released to the public "in a day or two."

The intervention being considered by the U.S. would be of limited scope and duration, The Washington Post reported Monday. It would be meant to both punish the Syrian regime and deter it from using chemical weapons in the future.

“We’re actively looking at the various legal angles that would inform a decision,” an official told the newspaper.

In the most forceful U.S. reaction yet after the suspected gas attack, Kerry said Monday that Obama "believes there must be accountability for those who would use the world's most heinous weapons against the world's most vulnerable people."

There were mounting signs that the United States and Western allies were laying the groundwork for some kind of military response to the incident, which took place a year after Obama declared the use of chemical weapons a "red line" that would require strong action.

Obama, who withdrew troops from Iraq and is winding down the conflict in Afghanistan, has been reluctant to intervene in two and a half years of civil war in Syria.