US-Backed Syrian Rebels Undecided on Peace Talks LONDON - Today, another troubling sign of just how difficult and complicated the Syrian peace process has become. After weeks of aggressive cross-continent diplomacy - including a third face-to-face meeting today with Syrian opposition President Ahmad al-Jabar - Secretary of State John Kerry says he and U.S. partners have still not secured a commitment from moderate Syrian opposition forces to attend a planned peace conference in Geneva next month. I believe the conference can happen next month. I'm hoping it will happen next month," Kerry said today following a meeting of the so-called "London 11″ backing the Syrian moderates. But obviously there are other players...They are independent and they have to exercise their own rights here. Those players are opposition groups that have been disillusioned with the U.S. after a decision by President Obama last month not to strike the Bashar al-Assad regime for its use of chemical weapons, and who face increasingly daunting conditions in battle on the ground. U.S. officials say the moderate opposition is being hampered by an influx of al-Qaeda affiliated extremist fighters onto the battlefield, essentially forcing them to fight on two fronts. They are also facing shortages of western-supplied aid - both lethal and non-lethal - because of border crossings blocked by extremists. Jabar has agreed in principle to attend Geneva talks, but it's unclear how much influence and support he has among the broader opposition movement. The Syrian National Council plans to meet next month to discuss participation at Geneva. "We respect the process by which they need to decide if they come to the table," Kerry said today. You can win at the negotiating table, but it may take a long time and lot of lost life and destruction to win on the battlefield, and I think they see that. On the issue of preconditions to a peace conference in Geneva next month, Kerry said that he, the London 11, and Syrian National Council leadership have none other than a commitment to the principles of an earlier agreement among the parties - including Russia - that a political transition must take place by "mutual consent." The opposition is not saying that Assad has to go before this negotiation. That is not what they're saying," Kerry said. You can't have mutual consent if you're not talking to anybody. You have to go, engage in the discussion and see. Kerry called today's meeting "very effective, focused." He said the goal was to "reaffirm the international community's strong commitment to ending the bloodshed in Syria and trying to bring stability to that war-torn country" through fulfillment of the Geneva I agreement. "The Geneva communiqué is more than a piece of paper and it should not be a forgotten level of diplomacy," he said. " It is a roadmap that leads to a new future... and it rids the country of violence extremist groups.