In a further bid to win congressional support, Secretary of State John Kerry appeared before the Senate Foreign Relations Committee along with Defense Secretary Chuck Hagel and General Martin Dempsey. In his comments, Kerry initially refused to rule out the eventual deployment of “boots on the ground,” saying he can’t take an option “off the table.”

Secretary of State John Kerry: “In the event there was a threat of a chemical weapons cache falling into the hands of al-Nusra or someone else, and it was clearly in the interests of our allies and all of us — the British, the French and others — to prevent those weapons of mass destruction falling into the hands of the worst elements, I don’t want to take off the table an option that might or might not be available to a president of the United States to secure our country.”

Kerry later walked back his comments on committing U.S. troops, saying the White House has no such plans. The New York Times, meanwhile, reports at least 50 CIA-trained rebels have now crossed into Syria from Jordan.