The leader of Kenya's opposition Orange Democratic Movement (ODM) has said he has called off a mass protest planned for Thursday in the capital, Nairobi.
Mr Annan said he would insist on a solution for Kenya and Africa's sake
Raila Odinga said he was responding to a request by ex-UN chief Kofi Annan.
Mr Annan is to meet President Mwai Kibaki on Thursday, as attempts to end the crisis over disputed presidential election results continue.
Earlier, skirmishes between police and youths broke up a memorial service for victims of the post-election violence.
Tear gas was fired into the crowds of mourners at a park in Nairobi after ODM supporters threw stones at police vehicles during a speech by Mr Odinga.
More than 650 people have been killed during the past three weeks, while 250,000 others have fled their homes.
The ODM had been planning a mass demonstration on Thursday to underline its anger at the result of the 27 December election, which it claims was rigged by President Mwai Kibaki and his government.
But after meeting Mr Annan, who is in Nairobi to try to find a political solution to the election dispute, the ODM said it would call the protest off.
"On the request of the mediation team, we have called off the activities that we had planned for tomorrow to give this mediation the best chance," ODM MP William Ruto told KTN television afterwards.
"We believe as ODM that given a good chance, we can get out of the quagmire that our country is embroiled in."
Mr Ruto said the party had presented its evidence of electoral fraud by the government to Mr Annan and expressed its full confidence in his efforts to resolve the crisis in the country.
Previous demonstrations have been blocked by the security forces
Before the meeting, the former UN secretary general said he would insist on a solution for the "sake of Kenya and its people and for the sake of Africa".
He is being accompanied by Graca Machel, the wife of former South African President Nelson Mandela, and former Tanzanian President Benjamin Mkapa.
Mr Annan had planned to meet both sides on Wednesday, but was prevented because Ugandan President Yoweri Museveni, who is on a separate mediation mission, talked to Mr Kibaki for longer than expected.
Mr Annan was forced to postpone his meeting at State House for 24 hours.
Earlier on Wednesday, the air at one of Nairobi's parks was thick with tear gas as riot police fired canisters into crowds of people who had gathered for a memorial service.
The wooden coffins of those killed in last week's crackdown on opposition protests had been taken from the mortuary and laid out on the ground for people to pay their respects.
ODM youths were outraged by a police presence at the service
Hundreds of mourners had gathered round to listen to prayers and speeches and Mr Odinga was finishing his speech when tear gas canisters started to fly.
Reports say a group of ODM youths were angered by the presence of police at the venue and started pelting their cars with stones and the meeting then descended into chaos.
The protest moved down the street, with demonstrators later setting fire to the telephone exchange building where the government-owned telecommunications company Telkom was based.
The opposition has filed a complaint with the International Criminal Court, accusing the police of using excessive force during last week's protests, in which more than 30 people died.