"I have not hidden the fact that I think that there is a lot of room for improvement on both sides concerning road map obligations," Rice told reporters as she flew to Santiago, her final stop on a two-day trip to Brazil and Chile.
"Frankly, not nearly enough has happened to demonstrate that the Israelis and the Palestinians fully understand ... what is a very clear view to me - that without following Road Map obligations and without improvements on the ground, it's very hard to sustain this process," she added.
'Not surprised by Barak's absence'
US Gen. William Fraser met on Friday with Israeli and Palestinian officials to provide a US assessment of how well they have kept their promises under the 2003 US-backed Road map peace plan.
Meanwhile, Rice said that she was not surprised by Israeli Defense Minister Ehud Barak's decision not to attend Friday's three-way meeting with Fraser and Palestinian Prime Minister Salam Fayyad.
She said she had discussed this with Barak some time ago and knew Israel would be represented by senior Defense Ministry strategist Amos Gilad.