Rice said: "Right now, it [Syria] appears to have aligned itself with the forces of extremism.
"I will talk to anybody, anywhere, any time, under the right circumstances if I think we can make progress.
"But we have had, over the course of this administration, discussions with the Syrians, talks with the Syrians, envoys to the Syrians, and nothing has ever changed in their behaviour."
She said she had been doing some "deep thinking" about US policy in Iraq but did not see any easy solutions to the violence there.
She said: "I don't think that there are any magic bullets about Iraq. This is a complicated place.
"They are in a very difficult time. It will take some combination of Iraqi responsibility for their politics and also ... increased responsibility for their security as well as better help from the neighbours in supporting Iraq as it makes this very difficult transition."