Mombasa will be the third county to host a Building Bridges Initiative consultative forum.
The meeting will be held on January 25.
The agreement was reached on Monday following a meeting held by ODM party leader Raila Odinga with governors from the coastal region.
The first forum was held in Kisii on January 10.
Kakamega was the host of the second forum held on Saturday, which was attended by Raila, ANC leader Musalia Mudavadi, Ford Kenya leader Moses Wetang'ula among other leaders.
Addressing residents, Raila said he does not have to be the president and that the politics of 2022 will come and go.
He added that the country needs a posterity solution, which he said was BBI.
"What I am doing with Uhuru is for posterity for this country. It is not Raila Odinga. Raila Odinga does not have to be the President of Kenya. But Kenya must have a good President," Raila said.
Western region endorsed the report as Mudavadi cautioned leaders against using BBI to cause rifts with fellow leaders.
"Kuna wengine hapa ambao juhudi yao ni kuleta porojo ambayo haina misingi,(there are some whose agenda is to bring gossip)," he said.
He added that the report should be about the public and should address the problem that is ailing the economy.