By Arshad Mohammed

SANTIAGO, March 14 (Reuters) - U.S. Secretary of State Condoleezza Rice said on Friday neither Israel nor the Palestinians have done "nearly enough" to meet their obligations under a 2003 peace plan, making it difficult to sustain the U.S. push to end a six-decade conflict.

"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.

U.S. Gen. William Fraser met on Friday with Israeli and Palestinian officials to provide a U.S. assessment of how well they have kept their promises under the 2003 U.S.-backed "road map" peace plan.

Among other commitments, under the plan Israel was to cease all settlement activity and the Palestinian Authority was to crack down on Palestinian violence against Israelis.

Since last year's U.S.-hosted Annapolis peace conference, Israel has several times announced plans to build new settlement housing on land that the Palestinians regard as theirs. The Palestinian Authority, having lost control of the Gaza Strip to Hamas last June, has been unable to stop Hamas-launched rocket attacks on Israel.

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 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.

U.S. President George W. Bush hopes the two sides can reach the outlines of a peace agreement before he leaves office in January 2009, a prospect that appears remote.

(Reporting by Arshad Mohammed; Editing by Stuart Grudgings)

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