President Obama under pressure to intervene in Syria
After talks with Turkey's prime minister, President Obama made it clear the US will not unilaterally intervene in Syria.
However, he is facing pressure from those in Congress who believe that the US has to act.
Republican Senator, John McCain said: "An international force may have to go in depending on the circumstances to secure these chemical stocks."
He added "That does not mean the United States alone but I would argue that it is in everybody in the World's interest to see that these chemical weapons caches are secured."
The BBC's Mark Urban reports from Washington on the changing mood on Capitol Hill.