"Secretary Rice doesn't expect, I don't think, to come away with a final deal," White House spokeswoman Dana Perino said. "But I do think ... they are inching their ways closer and they need a little bit of help to get there."

President George W. Bush is sending Rice to Nairobi to help push along mediation led by former U.N. chief Kofi Annan.

Bush, who is in Tanzania on the second day of a five-nation African tour, said earlier he did not want to dictate how to bring an end to Kenya's political violence but wanted to help Annan.

Bush said he and Rice had discussed with Tanzanian President Jakaya Kikwete "how best we can help the process. Not what we should do to dictate the process but what America can do to help the process move along".

The U.S. president has thrown his weight behind a power-sharing deal in Kenya to end a standoff over President Mwai Kibaki's disputed re-election which triggered a wave of ethnic killings.

One thousand people have been killed and 300,000 left homeless in the crisis, one of the bloodiest chapters in Kenya's post-independence history.

Annan has said considerable progress was made in talks this week, including agreement for an independent review of the polls. Experts say an agreement on power-sharing terms is the major sticking point.

In an effort to shore up Annan's mediation, U.S. officials said the United States was ready to sanction any individuals who sought to obstruct Kenyan peace moves.

Perino said Rice would not be bringing any incentives with her to Nairobi to encourage the two sides to reach a deal.

She said in talks on Sunday Kikwete told Bush he appreciated that the United States was willing to support Annan's mediation efforts.

"President Kikwete said there is sometimes a belief that Africans can't solve African problems and that somebody from the West has to come and try to solve it for them," Perino said.