Deputy Spokesperson Mark Toner released the followed statement on violence in Syria on December 23, 2011. He said:
"The United States condemns in the strongest terms the bombings today in Damascus. We extend our sympathies to the families of the victims. There is no justification for terrorism of any kind and we condemn these acts wherever they occur.
"For nine long months the Assad regime has used torture and violence to suppress the aspiration of the Syrian people for peaceful political change. Throughout this time we have spoken out against the violence in Syria, as we have in other countries since the moment peaceful movements for democratic change began in the region, and we will continue to do so. It is crucial that today's attack not impede the critical work of the Arab League monitoring mission to document and deter human rights abuses with the goal of protecting civilians. We hope that this mission will proceed unfettered in an atmosphere of non-violence. The burden is on the regime to cooperate fully and quickly with the monitoring mission.
"The Syrian people continue to suffer daily. They deserve a peaceful political transition that begins with respect of their human rights and an immediate end to repression. The United States will continue to support the Syrian people in their struggle for a peaceful transition from dictatorship to democracy."
You can also find the statement here.