Kenyan opposition leader Raila Odinga.(AP Photo/Khalil Senosi)

Kenya's opposition leader is rejecting U.S. advice to cancel a planned mock inauguration of him as president, saying he doesn't recognize the legitimacy of President Uhuru Kenyatta.

Raila Odinga alleged Thursday that dozens of Kenyans have been killed by the security forces and "nobody is talking about it. Yet they have the audacity to come and advise us to forget and move on."

He spoke outside a morgue in the capital Nairobi while accompanying families collecting bodies of the police's alleged victims.

A U.S. Embassy statement Wednesday called Odinga's planned protest event on Dec. 12 "extra-constitutional" and urged him to cancel the event.

Odinga successfully challenged Kenyatta's August re-election but then boycotted a rerun vote in October, demanding electoral reforms. Kenyatta was inaugurated last week.