Obama continues to evaluate U.S. involvement in Syria

Barack Obama warned that U.S. forces could move against Syrian leader Bashar al Assad if he deploys chemical weapons or rebels trying to overthrow him.

Obama said al Assad faced "enormous consequences" if he moves toward using the weapons in a threatening manor, Reuters reports.

Obama has refrained from ordering U.S. military engagement in Syria. At a recent conference, though, Obama outlined his continuing evaluation of the situation.

"We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized," Obama said, Reuters reports. "That would change my calculus."

While Washington and its Western allies have not responded to Assad's actions as they did with Libya's Muammar Qaddafi last year, Obama explained that their methods could change under certain conditions.

Iran, Russia and China, however, have shown resolute support for al Assad, according to Reuters.

Syria acknowledged for the first time its possession of biological weapons, warning that it could use them if foreign countries intervene in the conflict. Washington and its allies warned against this threat. Obama said that he is not absolutely confident the stockpile was secure.

Obama has called on al Assad to step aside and allow for a democratic transition, but is reluctant to involve the United States in another war in the Middle East. He has also refused to arm rebels, Reuters reports.