"Once we establish the facts, I have made clear that the use of chemical weapons is a game changer," Obama said in a news conference with Israeli Prime Minister Benjamin Netanyahu. Obama said he wouldn't announce what the next steps would be while the investigation is unfolding. But he echoed his statement over the summer that the use of chemical weapons in Syria would be a "red line" for the United States.
"When you start seeing weapons that can cause potential devastation and mass casualties and you let that genie out of the bottle, then you are looking potentially at even more horrific scenes than we've already seen in Syria. And the international community has to act on that additional information," Obama said.
"We have been clear that the use of chemical weapons against the Syrian people would be a serious and tragic mistake," Obama said.
Obama said the U.S. policy not to intervene militarily thus far is based on his desire to solve the problem as a global community. "It's a world problem ... when tens of thousands of people are being slaughtered, including innocent women and children," Obama said.
Netanyahu said the two leaders discussed Syria during their private meeting earlier. He said the two countries share a goal of preventing Syria's weapons arsenal from falling into the hands of terrorists.
Obama said the United States shares the concern that the weapons could be transferred to a group like Hezbollah and used against Israel. "The Assad regime must understand that they will be held accountable for the use of chemical weapons or their transfer to terrorists," Obama said.