UN emergency relief co-ordinator John Holmes has called for a peace deal after visiting some flashpoint areas of violence after Kenya's disputed polls.
A quarter of a million people have been displaced since the elections
The envoy's visit comes at a time of renewed hope that a political solution to the crisis can be found at talks.
Mediator Kofi Annan is urging patience but said a deal on political issues could be settled by next week.
About 1,000 people have been killed and more than a quarter of a million people made homeless in the post-poll unrest.
Mr Holmes visited camps in Kenya's western Rift Valley which have seen some of the worst fighting following December's disputed election result.
The envoy told reporters he had come to see for himself the extent of the displacement that has been triggered by inter-ethnic fighting, and was lending support to mediation efforts being spearheaded by Mr Annan.
"Everybody's hoping that there will be some kind of deal done in Nairobi which will help to maintain the fragile calm which we've seen returning in the very recent days to areas like this," Mr Holmes said in Nakuru, where 11,000 people have been made homeless, and many of them are camped out in a sports stadium.
"The alternative, if there's no deal, I think is much more worrying in the sense that that could then serve as a cause to reignite the violence and then we see more people being displaced and this tragedy really getting much worse that it is now," Mr Holmes told the BBC.
"We are tired. There is no food and no blankets. And I don't think the violence will end," AFP news agency quoted 32-year-old Idi Abubabakar as telling Mr Holmes.
Mr Holmes has called for a peace agreement
Mr Annan said he expected that the political issues that separated the two sides could be settled by as early as next week.
Although no final deal has been struck it is understood that President Mwai Kibaki's party and the opposition are beginning to talk of an interim power sharing arrangement, but exactly how this would work and how long it would last, are details that still need to be thrashed out.
Any agreement is expected to include binding commitments to land reform, constitutional change and a shake-up of the courts, the BBC's Karen Allen says.
"In negotiations, a deal is not a deal until it is done," the former UN chief warned in a statement.
"While the talks are making progress, they have not come to a definite conclusion."
In Western Kenya, thousands of mourners, including opposition leader Raila Odinga, have attended the funeral of MP David Kibutai Too who was killed during the violence.
The newly-elected MP was shot dead by a traffic policeman in the Rift Valley town of Eldoret.
The funeral is the first public mass gathering since a ban on rallies was lifted on Friday.
Mr Odinga told his supporters at the funeral that any deal struck would not jeopardise "justice for Kenyans".