Bernat Armangue, Associated Press
Children sleep on a bed at the SOS Children's Village Nairobi in Nairobi, Kenya. Relief workers are looking for their parents.

NAIROBI, Kenya — Kenya's political parties have agreed to an independent review of the country's disputed presidential election but have not yet reached a consensus on the crucial issue of a political settlement, former U.N. secretary general Kofi Annan said Friday.

Negotiators for President Mwai Kibaki and opposition leader Raila Odinga, who accuses Kibaki of stealing the election, signed an agreement that calls for an independent commission to review "all aspects" of the election.

The commission, to be composed of Kenyan and non-Kenyan experts, will start work next month and submit its report within three to six months.

The findings must be factored into comprehensive electoral reforms, the agreement says.

More than 1,000 people have been killed and an estimated 600,000 displaced in violence since the Dec. 27 election.

But the country quieted in recent days as the talks entered the critical phase of negotiating a power-sharing government.

Annan, who is mediating between the two sides, said progress on that issue was taking longer than he had expected.

"We are at the water's edge, and the last frightening step will be taken," Annan said, adding later: "When it comes to the essential final step, people are scared, they balk and they have to get rid of inhibitions."

Many international observers have said the vote tally was so flawed that it is impossible to know who won, while some have said victory was stolen from Odinga.

Opposition leaders have accused the government of stonewalling in order to exhaust Annan so that he will leave before a deal is reached. On Friday, Annan vowed that he "will not be frustrated."

If a deal is not reached, he said, "it's going to be very difficult for Kenya."

The post-election crisis has unbridled longstanding ethnic tensions over land and resources, and a sense among many of the country's 42 tribes that they have been marginalized by a government dominated by Kibaki's Kikuyu tribe.

Most of the violence has occurred across the volatile western region of Kenya, where Kikuyus have been ousted from land that the Kalenjin tribe, which was loyal to Odinga, believes was acquired through shady resettlement schemes after Kenya's independence from Britain in 1967.

The land disputes are deeply rooted in Kenya's colonial history, when the British began grabbing vast swaths of land, especially in the country's Central Province, ousting the Kikuyu from their homeland.

Annan has said that any political settlement must address those fundamental causes of the crisis.

U.S. Secretary of State Condoleezza Rice is expected to be in Nairobi, the capital, when negotiations resume Monday. President Bush is also visiting the region, though he has no plans to visit Kenya.

Annan said Friday that international pressure on both sides would remain intense.

In an elliptical reference to hard-liners who may be frustrating the negotiations, Annan said: "A caravan moves at the speed of the slowest coach, unless we find a way to hasten that coach."